As of 2021, he plays for Cheegle Ekaterinburg, a professional volleyball team in the Russian Volleyball Super League. He is also a member of the Japan National Volleyball Team.
Standing at 165 cm, Yaku is on the shorter side. He has brown eyes and short sandy blond hair. Yaku is usually seen wearing the Nekoma training uniform. During matches, he wears the libero uniform consisting of a white jersey with red and black accents, red shorts, and knee pads. When playing, he normally wears white gym shoes with yellow accents.
Post-timeskip, Yaku's appearance has changed very little although his hair appears to be slightly longer and is now kept neatly combed back from his face.
Overall, Yaku is a rather honest, straightforward, and hardworking person who's very confident about his skills as a libero and looks out for his team; especially first-years Lev and Shibayama, and Kenma. He will frequently engage in light-hearted scuffles with his juniors, and will sometimes eat their food too.
Despite this, he can also be incredibly short-tempered, especially concerning Lev, who seems to find Yaku's angry outbursts "scary"; although these outbursts are typically in response to Lev tactlessly commenting on Yaku's height and/or attempting to skip practicing receives with him. Even Kuroo at times refers to him as a "demon senpai". Yaku has also been shown to be insecure about his short height and it is well known to be a taboo subject of discussion amongst the Nekoma players.
Yaku takes great pride in playing as libero, and especially considers it a huge honor to play as libero for Nekoma, a team whose members specialize in powerful defense. Off the court, he is supportive of his team and often takes on a parental role when speaking toward, or of them, which is similar to Sugawara. Because of this, Yaku and Sugawara are known to get along well.
Upon joining Nekoma's volleyball club, Yaku and Kuroo started off with a rocky relationship due to Yaku's middle school having badly defeated Kuroo's middle school in the past, although Yaku claimed he did not remember this. The two often got into arguments and seemed to disagree on everything. Despite their differences, when asked about their goals when joining the volleyball club, Yaku, Kuroo, and Kai all agreed that they aim to win nationals, and this seemed to leave the three players' relationship on good terms.
Karasuno High Team Formation Arc
Yaku is introduced as Nekoma High's third-year starting libero as he first meets Sugawara when apologizing for their teammates’ rough behaviors after stopping an attempt from Yamamoto and Tanaka to fight when they were each defending their teammates. Shortly after the game starts, Yaku becomes awed at the Karasuno’s rookies’ quick attack and is amazed at the range and speed used.
During the game, Yaku makes multiple excellent saves, either to pass to the setter or simply to dig. In the second set, however, Yaku bumping Asahi’s harsh serve especially attracts the attention of Nishinoya. Despite this clean pass, Yaku lets way for a free ball when bumping another of Asahi’s shots.
After the matches end, Yaku notices Nishinoya looking at him intensely. Noticing this, Sugawara apologizes for his behavior and tells the older libero to ignore Karasuno’s own. Abruptly, Nishinoya praises Yaku for his consistent digs and boldly claims to become a better libero than him one day before running off. When Sugawara apologizes once more, Yaku admits to finding Nishinoya’s sense of humility and constant drive for self-improvement a quality that he both admires and finds "terrifying."
Tokyo Expedition Arc
During the summer training camps, Yaku can mostly be seen participating in the practice matches or spending time with his own teammates or with Sugawara. On the first night of the first training camp, Yaku is joyful at seeing Kenma talking to Hinata without a hint of his usual shy demeanor.
During the week long camp, Yaku is revealed to be helping Lev try to improve his receiving; although Lev at one point ditched the practice to join the group in the third gym. Yaku later hangs out with Kai and Sugawara during the barbeque, where they watch several of their teammates acting silly and Yachi appear nervous around all the taller players. He joins several others in saying good-bye to Karasuno when the team headed back to Miyagi.
Tokyo Prefectural Qualifiers
Nekoma vs Fukurōdani
Not long before Nekoma's first match, Yaku does not get surprised and becomes annoyed when Kuroo and Suguru start taunting each other. When Lev comes back from the bathroom, Yaku scolds him for slacking off. When on the court, Yaku congratulates Akane for her performance in leading the cheering squad, but also takes time to admire Alisa. During the game’s first rally, Yaku is able to save Sarukui’s powerful jump serve.
Yaku left a rather huge impact during the Tokyo Expedition arc, during which the role of the libero's position was explained in depth. During the Tokyo representative match between Nekoma and Fukurōdani, Nishinoya explains to Hinata that truly skilled libero's are players that manage to not stand out, but whose presence on the court ensures their teams' victory. Even Bokuto stated that Yaku's receives "give him chills" and he acknowledges Yaku's impressive defensive skills. This in turn inspires Bokuto to play even harder against Nekoma during the Tokyo Representative deciding match.
During break later on, Kenma notices Yaku having been in a perfect form that day and Yaku happily confirms this. Sometime later, when Lev gets rotated in, Alisa cheers for him. Hearing this, Yaku tells Lev to step up as his sister was attracting more attention than he is. When Lev fails to hit Kenma’s set and the ball falls back on his head, Yaku becomes angry and some of Nekoma’s other rookies have to hold him back. Despite being angry earlier, Yaku makes sure to become wary of Bokuto being rotated to serve and tells the back row to take a half step back.
Yaku would confront Bokuto once more when managing a rough but successful overhand receive to one of the ace’s shots. Following Nekoma’s loss, Yamamoto is frustrated at how good Fukurōdani is. When Kuroo sees Lev being quiet when leaving the court, Yaku informs him that his failures in the last game had been eating him.
Nekoma vs Nohebi
After losing to Fukurōdani, Nekoma faces off against Nohebi High School for the third and final Tokyo Representative spot. During this match, both teams demonstrate impeccable persistence in maintaining their defenses, despite Nohebi's penchant for attempting to throw Nekoma off with a constant stream of feints, block-outs, and well-timed taunting. At one point, Yaku admonishes an increasingly frustrated Lev and tells him not to flail his arms aimlessly in an attempt to block the opposing spikers, as this makes receiving the ball extremely difficult. Lev angrily responds in turn that despite how he blocks, Yaku would certainly save the ball without fail; this outburst causes Yaku to be quite surprised and flattered until he is teased by Kuroo for losing his "demon senpai" image.
Later in the first set, Yaku leaped into the crowd in an attempt to save the ball which had been received off-kilter by Yamamoto. This successful display of athleticism and fast reflexes sent the crowd and his team into a frenzy, and ultimately allows Nekoma to score.
However, in the process of saving the ball, Yaku landed on a spectator's foot and sprained his ankle. He attempts to shrug off his teammates' concern but grimaces in pain when he tries to walk it off. He is then promptly led off the court for first-aid treatment, and Shibayama is called into the game as the back-up libero. In response to Yaku's tearful frustration, his fellow third years Kuroo and Kai tell him not to worry, and to consider being benched as a "brief vacation" while his team picks up the slack and secures the final spot to represent Tokyo at Nationals.
While sidelined and receiving first-aid, Yaku continues to watch his team closely. While doing so, he begins to worry when Kuguri seems to become a problem for Nekoma's blockers. Sometime later, Yaku would interrupt his ankle getting taken care of when admiring Lev smashing past Nohebi's defense. As the match progresses, he swells with pride when Shibayama successfully adapts to his role as libero.
He tearfully laughs and hugs each of his teammates after Nekoma secures their victory against Nohebi. As the team is leaving the court, Yaku listens as Kuroo admits Lev went beyond his expectations for the game. Yaku tells the captain that he should just be straightforward with Lev about how he plays and in return is teased about how not everyone is as confident as he is when it comes to receives.
Tokyo Nationals Arc
Nekoma vs Kiyokawa
Yaku played with Nekoma against Kiyokawa High. He and his teammates are seen making multiple receives that wear down Kiyokawa's ace. He was later seen celebrating with the others when Nekoma won the match.
Nekoma vs Sarukawa
Prior to the match, Yaku is relaxing with the team's third-years. He wishes that the nationals were farther away because he'd like to travel on the bullet train. He follows by being skeptical about Nekoma's future lineup about passing the qualifiers the next year. When spotting Kenma, he is amazed at how they managed to get him to nationals. When Kuroo explains that Kenma is grateful that he picked volleyball up, Yaku doesn't believe him. He then remembers Kuroo telling the team about Kenma's "early riser" incident and notices that he's gotten more determined after meeting Karasuno. After this, Kuroo and Yaku get into a short squabble about which of them will stand out the most.
During the match, Yaku roughly manages to save an impressive jump floater from Wakura. In a timeout, Yaku explains to his team him having noticed Sarukawa's attempt to tire Kenma. When Nekomata tells his team not to lose focus, Yaku boldly announces that he would do anything to protect Nekoma's setter. After Kenma tells the team to send the ball to him, they all proudly assure him that they would do so. Following their victory, Kuroo and Yaku are both proud of Kenma for being able to come up with a strategy despite his exhaustion.
Karasuno vs Inarizaki
After their match is over and Nekoma watches Karasuno's match against Inarizaki, Shibayama attempts to explain how the ball could go different ways after receiving. Lev claims he's understood, but Yaku isn't convinced. As he continues to watch, Yaku gets excited when seeing both of the teams' setters clash. Later on, Yaku yells at Lev, who is watching the game with the other first years, to pay attention to Suna and Tsukishima's blocking. Sometime later, Osamu keeps Karasuno waiting as he is about to serve and Yaku, although he is not playing, admits he hates the time gaps Osamu creates.
Nekoma vs Karasuno
Yaku is seen eagerly awaiting the match between Nekoma and Karasuno. He showed disappointment in seeing Lev make an off receive on Tanaka's spike. When he rotated into the game, he compliments Nishinoya for getting even better than when they last met after seeing the second year perform a jump set to Asahi.
When Fukunaga was blocked when Tsukishima and Yamaguchi perform the serve and block method, Yaku would kick Kuroo while blaming him for Tsukishima's increase in skill. In the next play, Yaku was able to receive Yamaguchi's serve that would allow Yamamoto to score and stop the first year's serve. After Shibayama tried to encourage Lev to play like himself but failed to get the message across, Yaku bluntly tells the middle blocker not to mess up.
For several plays, Yaku is mostly seen making receives and later seems to be the one designated with receiving most of Asahi's spikes; this continued well into the second set. When the score is tied 19-19, Yaku is seen lying in wait for Asahi's spike only for the ace to put too much power into it and have the ball land out. Bokuto is then seen warning Yachi that Yaku is a player capable of stopping a spiker without ever touching the ball.
At Hinata's next attempt using his new jump to spike past a triple block, Yaku is able to receive the spike. Several Karasuno players are able to figure out that Yaku manipulated the players into aiming exactly where he would be waiting. The play would earn great admiration from Nishinoya. Yaku would soon be surprised when Nishinoya was able to save the ball with the back of his foot and score a point for Karasuno.
Half-way into the set, Daichi appears to be doing a back attack and Yaku calls for everyone to move back a step. However, this would turn out badly for Nekoma when Daichi's spike hits the top of the net and lands in the front row with no one there to save it. When Karasuno is at match point, Yaku would save a ball but it goes directly back over the net where Hinata would do a direct spike only for Lev to suddenly appear and block it.
Nekoma would eventually lose the match. Yaku would shake hands with Sugawara and Nishinoya afterwards before walking off the court with a tearful Lev and Shibayama. He would join the team in thanking Coach Nekomata for being their coach. When Kai would voice how happy he was to have been able to play with Yaku and Kuroo as his teammate for the last three years, Yaku would burst into tears.
Karasuno vs Kamomedai
During Karasuno’s match against Kamomedai, Hoshiumi impressively receives Tsukishima’s spike after having been set to perfectly and Yaku is impressed at how good his receiving skills are. After Karasuno's loss, Yaku joins Kuroo and Bokuto in praising Karasuno for a well played game and tearfully hugging Sugawara.
Yaku's first appearance in the Final Arc is when he makes a stop in Shibuya while on the phone with one of his former teammates. He had stopped in Shibuya due to wanting to see the billboard that Lev and Alisa appear on and laughs when seeing it. Yaku is currently playing for Cheegle Ekaterinburg as a libero in the Russian Volleyball Super League. He returns to Japan to play as one of the liberos on Japan's National Team at the 2021 Olympics.
|High School Statistics|
Yaku's skills as a libero rival those of Nishinoya. He has a keen sense of receiving and can steadily dig Asahi's strong spikes despite having never faced him before, a feat which instantly earns him Nishinoya's respect during Karasuno's first practice match with Nekoma. Nishinoya has commented that one reason he admires Yaku is that he does not stand out much on the court, yet his defensive prowess is undeniably invaluable. Akane Yamamoto had also described him as the "Guardian" and "Commander-in-Chief" of Nekoma's defense, and regards him as a player just as important as the ace. His abilities have been praised by Bokuto, who has stated that "Yakkun's receives give me goosebumps!"
- Pre-Timeskip: 301 cm
- Post-Timeskip: 325 cm
|Post-Timeskip Skills Parameter|
- Receives: Similar to how Nishinoya is labeled as Karasuno's defensive specialist, Yaku is known to be Nekoma's greatest defender. He is incredibly gifted in being able to receive and dig powerful spikes from opposing spikers from people he has played against before or is playing against for the first time.
- Lev Haiba: Lev is Yaku's underclassman and "student" who he coaches regularly in receiving (much to Lev's dismay). The two appear to get along most of the time. However, Lev frequently attempts to escape Yaku's merciless coaching and will at times poke fun at the latter's height, which usually sends Yaku flying into a rage that will result in the libero hitting or kicking the middle blocker. Like the rest of his teammates, however, Lev has great respect and admiration for Yaku due to his impressive skill as a libero and his commanding presence on the team.
- Tetsurō Kuroo: Although Kuroo and Yaku played against each other in middle school, they didn't officially meet until they joined the volleyball club during their first year of high school. Because Yaku's team had easily beaten Kuroo's team and Kuroo was much taller than Yaku, their relationship started off very badly. They would often bicker and disagree on minor things, such as girls' hairstyles, summer activities, favorite foods, and even which brand of volleyball they preferred. One day during practice, all the freshmen members had to say their goals and aspirations out loud per the club's tradition. To everyone's surprise, both Kuroo and Yaku declared in unison that they wanted to "dominate nationals" despite their other teammates settling for making into Tokyo's top eight. This declaration ultimately helps them to put aside their differences and unite as teammates who trust each other. Kuroo has been shown calling Yaku various nicknames such as "Yakkun" and "Demon Senpai." At present, their interactions are far friendlier than when they first met.
- Nekoma High: Yaku is shown to be a supportive and guiding upperclassman toward many of the younger players. He is shown to be especially helpful toward first-year Shibayama when he helped the younger libero understand what it means to earn his way to becoming a regular player. Yaku appears to be quite close to Kenma as he has noticed how the setter has changed since meeting Hinata.
- Kōshi Sugawara: They first met during the Nekoma vs Karasuno practice match when Taketora and Tanaka were causing trouble. Sugawara and Yaku apologized to each other for their teammates and soon bonded over their similar positions of being caretakers for their teams. Yaku and Sugawara have a similar personality type, and are seen conversing in a friendly manner on multiple occasions.
- Yū Nishinoya: Yaku first encounters Nishinoya during the practice match between Nekoma and Karasuno. After the match had ended, Nishinoya approached Yaku while admitting that he found the Nekoma libero incredibly talented and would not lose to him during their next meeting. Yaku would admit to Sugawara that Nishinoya was the incredible one as he continues to push forward, making him a dangerous threat. During their match at nationals, Yaku and Nishinoya continued to praise one another's plays and are seen shaking hands when the match ended.
- "Yamamoto, stop immediately picking fights with people. It makes you look like an idiot." (To Yamamoto, Volume 4 Chapter 27 / Season 1 Episode 12)
- "[About Nishinoya] His skills as a libero are at such a high level, and yet far from being conceited, he just looks intently forward... That's pretty frightening." (To Sugawara, Volume 4 Chapter 34 / Season 1 Episode 13)
- "You know, getting nicks and bruises... that's the same as breathing for me. And this entire year, I've managed to avoid any serious injuries or illnesses... So why of all days did it have to be today?" (To Nekoma, Volume 22 Chapter 199 / The Path of the Ball)
- Favorite food: Stir-fried vegetables.
- Pre-timeskip Concern: His kouhai are causing him all kinds of worry.
- Post-timeskip Concern: Being charged as a child in ticketing.
- In an officially released chart from Monthly Volleyball 2020 August Issue, he is listed as 169 cm and 69 kg in July 2020. However, the final guidebook and the official illustration book both list him as 167 cm and 64 kg, indicating the statistic in the chart is an error.
- His birthday falls on World Cat Day.
- His star sign is Leo.
- Unlike Kuroo, he prefers meat, girls with short hair, spicy curry, Molten volleyballs, cats, and going to the mountains during the summer.
- Yaku is the second oldest of the Nekoma third-years.
- While people usually call him "Yaku", Kuroo and Bokuto were shown calling him "Yakkun", Lev calls him "Yaku san", and Nishinoya calls him "Morisuke".
- He was chosen as the libero on Furudate's Dream Team.
- His dub voice actor also voices Yutaka Obara and Jingo Fukiage.
- In Haikyuu's first popularity poll, Yaku placed 14th with 2,211 votes. In the second, he dropped to 19th with 2,979 votes.
- Morisuke (衛輔) - Protecting Help
- Yaku (夜久) - Long Ago Night