"The Final Boss" (Japanese: ラスボス Rasubosu) is the three hundred seventy-eighth chapter of the Haikyū!! series, written and illustrated by Haruichi Furudate. It was published in the 4th-5th issue of Weekly Shōnen Jump’s 2020 series.
Hinata and Kageyama are about to face off in their first official match since middle school with their respective professional teams, MSBY Black Jackals and Schweiden Adlers. Many familiar faces from high school, now have gone their separate paths, all gather at the Kamei Arena Sendai gymnasium to spectate the match.
In November 2018, Hinata has become an official member of MBSY Black Jackals. On the bus ride en-route to their next match, Hinata and Atsumu watch a recording of Heitor's beach volleyball match and laugh over Kageyama's awkward curry commercial. Soon enough, the team arrives at Kamei Arena Sendai, the venue where a V.League Division 1 match will take place.
The stadium is filled with various food vendor and delicious aromas. Some newer fans, not aware that Atsumu has a twin, are puzzled to find Osamu selling onigiri until a veteran fan corrected their misconception. Osamu and Yamaguchi recognize each other when the latter goes to buy onigiri. The two casually converse about not missing out on the match between the Schweiden Adlers and MSBY Black Jackals, noting that it's the first time Hinata and Kageyama play each other in an official match since middle school. Meanwhile, Hinata and Kageyama come face to face in the corridor in front of the men's restroom.
Yachi soon arrives to purchase konnyaku skewers from Shimada Mart's stand nearby. Tsukishima is already in the seating area browsing through the players guide. Shortly after Hinata came back from Brazil, Yamaguchi met up with Tsukishima and presented him with a sparkly pink shirt that Hinata insisted to be given to Tsukishima despite any objections. Tsukishima inquired about Hinata's reasoning for choosing Black Jackals and found out that Hinata picked the team because they are the best team running tryouts. Tsukishima noted this be a very Hinata-esque thing to do as he recalled their conversation in high school after Hinata unveiled his plan to switch to beach. Hinata was serious about using beach volleyball to train and aimed to become good enough to get on a team with a great setter.
Back to the present time, Yamaguchi and Yachi join Tsukishima in the spectator stands. Daichi, Sugawara, and Asahi have also reunited inside the gymnasium. Despite separating and having different careers, the three joke around like old times and recall the vivid memory when they clinched their first ticket to the nationals years ago. Sugawara shouts out in excitement for the upcoming match. In the Adlers' changing room, Hoshiumi is highly anticipating facing off Hinata again.
- Kenma Kozume
- Shōyō Hinata
- Heitor Santana
- Atsumu Miya
- Tobio Kageyama
- Kōtarō Bokuto
- Osamu Miya
- Tadashi Yamaguchi
- Ittetsu Takeda (Flashback)
- Yūsuke Takinoue
- Makoto Shimada
- Hitoka Yachi
- Kei Tsukishima
- Asahi Azumane
- Daichi Sawamura
- Kōshi Sugawara
- Wakatoshi Ushijima
- Kōrai Hoshiumi
- Hinata is revealed to have pass MSBY Black Jackals' audition and wears the #21 jersey.
- Heitor and Nice are expecting a child soon.
- The V. League Men's Division 1 poster shows Motoya Komori and someone who resembles Aran Ojiro on other teams.
- Yamaguchi is revealed to have picked up Hinata from the airport when the latter came back from Brazil.
- Hoshiumi is an outside hitter on Schweiden Adlers.
- The careers of many characters are revealed:
- Osamu has opened up a ongiri shop called "Onigiri Miya."
- Yamaguchi - college senior, will work for a home electronic company next year.
- Tsukishima - college senior, starting work for The Sendai City Museum, and is a middle blocker on Sendai Frogs (V. League Division 2).
- Asahi - Apparel Designer (Tokyo).
- Daichi - Miyagi Prefecture Police Force Community Safety Division.
- Sugawara - Elementary School Teacher (Miyagi).
- This chapter includes a colored double page of Hinata, Atsumu and Bokuto in their Black Jackals uniforms.
- Japan's Professional Volleyball League consists of three levels: Division 1 (Top), Division 2 (Middle), and Division 3 (Bottom).
- Following the previous chapter, this marks the second consecutive time jump. Chapter 377 jumps from Fall of 2017 to March 2018 and Chapter 378 jumps to Nov 2018.
- Kamei Arena Sendai is renamed from the old Sendai City Gymnasium after the supermarket company, Kamei Corporation, acquired its naming rights in 2016.