He has a dark ginger hair and slanted, dark brown hooded eyes. He is very tall for a second-year, and has a considerably large build. He can usually be seen with a flat expression or scowl.
He doesn't talk to his teammates very often, and appears mostly emotionless, only looking annoyed on occasion. He is generally seen to be a competitive person, cheering every time he scores, and crying upon his team's loss to Karasuno. His upperclassmen have implied that Kawanishi is uncertain about himself or his abilities, with Ushijima telling him to gain more confidence moving forward, and Tendō noting that he doesn't go for aerial battles unless he knows he can win.
Spring High Preliminary Arc
Kawanishi is part of the starting line-up in the match between Shiratorizawa and Karasuno. After Daichi's first serve lands out, Kawanishi is first to serve for Shiratorizawa. He is able to score a service ace as the Karasuno players are so nervous that Asahi and Tanaka called to make the receive at the same time but hesitated at the last moment. Although his next serve is picked up, Ushijima is able to score a point and put them ahead at 3-0.
Near the end of the second set, Kawanishi attempts to block Hinata when he performs a back attack but is unable to make it. This results in the blocker getting scolded by Tendō, even though Kawanishi felt it was clear that there was no way he could have stopped the ball. In the fourth set, Karasuno launches a synchronized attack. Kawanishi finds himself annoyed at seeing the attack again. Despite this, he suddenly appears to block Asahi. It's revealed that he was able to figure out who would attack when he saw that Daichi would not make it in time to join the attack since he had been the one to receive Ushijima's spike.
As the score became tied at 20-20 in the fourth set, Kawanishi begins to realize that Karasuno would not allow Hinata to exhaust himself so quickly and that sees that he should concentrate on other attackers. At this, he is able to deflect Daichi's spike and eventually land the counter attack. After Yamaguchi is subbed in, Kawanishi attempted to block Tsukishima but was surprised when he suddenly used a time difference attack.
In the fifth set, Karasuno eventually reaches match point at 20-19. Shirabu entrusts Kawanishi with the ball for a center attack since the setter is cautious of Tsukishima being at the net and knowing that a time difference attack will not work on him. Despite Kawanishi's best attempt, Tsukishima is able to deflect the spike. This leads to Karasuno attempting to counter. Kawanishi attempts to block Hinata's spike but panics when the ball simply ricochets off his arm. Ushijima is able to keep the ball alive though. Kawanishi is able to block Asahi. The ball is saved by Tanaka and Kawanishi, being cautious of Hinata, notices that the Karasuno middle blocker is not rushing ahead of everyone else. With Yamagata unable to receive Hinata's spike, Karasuno wins the match. Kawanishi and his teammates leave the court upset at their loss. When they return to the school, the third years retire from the team. Before Ushijima leaves, he offers advice to the second and first years. He acknowledges Kawanishi as the cornerstone of the blockers but asked the blocker to strengthen his serves as well as having more confidence in himself.
As of November 2018, Kawanishi has become a part-time bartender and college senior in Tokyo. Semi and Reon are the only ones from his former team to be able to make it to the game between the MSBY Black Jackals and Schweiden Adlers and inform Tanji Washijō that Kawanishi is unable to attend the game due to work and financial issues as a college student. 
|High School Statistics|
He doesn't seem to put much effort into his playing and sometimes accidentally lets a ball in; however, since he's a starting member in Shiratorizawa, his abilities shouldn't be too low. Tendō has noted that Kawanishi has an eclectic and more analytical blocking style, which the third year's a little annoyed by. His playstyle is stated by Tendō to be "omnivorous". Kawanishi primarily uses read blocking during matches, but, when he's in the zone, he switches to guess blocking. During their match against Karasuno, he demonstrated commit blocking against Hinata. It's been said that he doesn't fight battles he cannot win.
Due to Shiratorizawa's Spartan-like training regimen, Kawanishi, like most of the team, has an above average amount of stamina. He can play long matches without getting noticeably exhausted.
Kawanishi's high game sense and intelligence factors into his read blocking ability. After seeing Karasuno's synchronized attack once, he's able to break apart and shut down their subsequent attempt at another. When he's upfront, he directs the three-man blocks.
By National Finals, he became an unpredictable and accurate server, being able to serve at corners and the next one clipping over the net, where both being service aces.
Jumping Reach: 330 cm
Of all the Shiratorizawa regulars, Kawanishi appears to get along the best with Shirabu, most likely due to being in the same grade level. Shirabu is comfortable enough to call Kawanishi by his first name. After pulling off successful combo plays, the two are seen amicably high fiving each other throughout their match against Karasuno.
- Favorite Food: Sukiyaki
- Current Concern: My allergies may be acting up...
- His star sign is Aries
- His hair color is darker in the anime than the manga.
- Taichi (太一) - Big one
- Kawanishi (川西) - Western river