|Date of birth||November 10|
|Height||184.2 cm (6' 0.5")|
|Weight||71.5 kg (157.6 lbs)|
|Home town||Miyagi Prefecture|
|Team||Date Tech High|
|Number|| 6 (Interhigh) |
2 (Spring High)
|Position|| Wing Spiker |
Captain (Spring High)
|Occupation|| High School Student |
(2nd Year, Class A)
|Affiliation||Date Tech High|
|Episode||"A Toss to the Ace"|
|Image gallery (38)|
Futakuchi is of above-average build and one of the tallest players on Date Tech. He has short brown hair, with his bangs falling naturally in a side swept style. His eyes are sizable and brown with narrow eyebrows.
He originally wears the number 6 jersey during the Interhigh and changes to number 2 after the third years retired. Outside of matches, Futakuchi is usually seen wearing the Date Tech Boys' Volleyball Club's tracksuit, which consists of teal pants and a white jacket with teal collars and sleeves.
According to Moniwa, Futakuchi is a problematic junior with an easy-going personality. He doesn't show much respect to his seniors and is often seen arguing with Kamasaki, who takes everything seriously. He also likes to provoke or taunt others, such as when he blocked Asahi saying, "Hey, what was that? He’s supposed to get dejected."
Despite his flippant attitude, Futakuchi does care about his teammates. He is shown to be affected when Moniwa announces the third years' retirement after their loss in the Interhigh. When Futakuchi becomes the captain, he grows more responsible while still keeping his provocative nature. He begins to give off a more serious vibe and spends most of his time keeping the new setter, Koganegawa, in line. With the roles switched, Futakuchi now understands being in the third years' shoes and admits to being a troublesome junior before.
Futakuchi, along with Aone, is an important component to Date Tech's Iron Wall even as a first year. He faced off against Karasuno in the 68th Prefecture Sporting Competition Volleyball Tournament the past March before the start of the story. He is one of the blockers responsible for shutting down Asahi's spikes. Despite being a second year, he is already the ace of Date Tech.
Futakuchi and Date Tech run into Karasuno on the first day of the Interhigh Preliminary. Following Moniwa's instructions, he stops Aone from "locking on" to Karasuno's ace, Asahi. Before they left, Futakuchi makes sure to let Karasuno know that Date Tech will stop them just like the last time. 
After Karasuno defeated their first round opponent, Futakuchi, Aone, and Moniwa are seen wondering about the short Karasuno number 10, who has attracted attention for hitting a crazy quick set. They deduce that Hinata must be a first year and becomes wary of him.  Later when Date Tech's match against Karasuno begins, Futakuchi is surprised to find Karasuno starting their ace in the back row. They soon realized that Asahi has increased his repertoire by adding a back row attack. However, Date Tech manages to shut Asahi's spike down easily with their iron wall. Futakuchi sees Asahi acting cheery and reveals that he want to see Asahi's spirit break before being scolded by Moniwa.
Date Tech maintains a high momentum by successfully shutting down Karasuno's attacks. However, they are soon left in the dust when Karasuno reveals their God-like quick. Afterwards, Futakuchi and Aone struggle to block Hinata at the right timing. Still, he manages to exert some pressure on Karasuno with his jump serves, often forcing a botched receive from Karasuno. Date Tech puts up a good fight but Karasuno reaches match point first. With Futakuchi, Aone, and Moniwa in the front row, Date Tech is at their strongest blocking formation. They manage to stop Asahi's spike multiple times, but finally Asahi's spike breaks through when the ball lands on top of the net before falling on Date Tech's side. Futakuchi chases after the falling ball but misses it by a hair to give Karasuno the ultimate victory.
After their loss, Futakuchi, along with Aone, proclaims they will get revenge in the Spring Interhigh Prelimary. He is seen flubbergasted when Moniwa tells them that the third years won't be there anymore and the responsibility will fall to the rest of the team. Futakuchi is reluctant but eventually accept the third years' decisions to retire. Sometime later at Date Tech, Aone and Futakuchi overhear the third years crying over their loss and the end of their high school volleyball career. The two become even more determined to avenge their loss. 
Spring High Preliminary ArcEdit
Futakuchi is one of the most skillful players on Date Tech. He is the ace of the team and has always been one of the three blockers that make up Date Tech's Iron Wall. He can spike decently but admits to not being good at spiking off extremely high tosses. Futakuchi also has a solid jump serve that can be used consistently.
Jumping Reach: 325 cm
- Read Blocking: Like the rest of the Date Tech blockers, Futakuchi excels in read blocking. The team employs a bunch shift where multiple blockers stay together to stop one spiker. This requires excellent read blocking skills since the blockers need to stay synchronized.
- Jump Serve: Futakuchi is currently the only one on Date Tech to be able to use a jump serve reliably. He has a powerful serve that can break opponents' formation to make it easier for his teammates to block in what is noted to be a perfect example of serve and block. 
Futakuchi and Aone are good friends. Upon Moniwa's request, Futakuchi is the one stopping Aone from intimidating Karasuno. In return, Aone keeps Kamasaki and Futakuchi in control whenever Futakuchi provokes Kamasaki. Futakuchi appears to have a good understanding of Aone and can read his intention from a single gesture without further explanation from Aone. On the court, the two are good partners. Futakuchi and Aone are both standout players on the team as the ace and the defensive stronghold. They would occasionally do a chest bump that usually ends with Futakuchi falling over due to Aone putting in too much power.
Futakuchi likes to provoke Kamasaki despite the latter being a year senior. He doesn't show much respect and would tease Kamasaki over trivial things like his job search or gaining too much muscle. The two would often get into petty arguments before being forcibly separated by Aone. However, there's no real hostility beyond their banter. After retiring from the team, Kamasaki and the other third years still come and support their juniors. He is delighted to find that Futakuchi is having trouble dealing with their rookie setter, Koganegawa.
Futakuchi is shown to have trouble dealing with Koganegawa's antics, often having to keep him in line and point out his mistakes. Koganegawa claims to understand, though it's debatable whether he actually gets what Futakuchi is saying.
- Favourite Food: Sour gummies
- Current Concern: He has to go and get his wisdom teeth pulled.
- He shares a birthday with Tadashi Yamaguchi.
- His star sign is Scorpio.
- In Haikyuu's first popularity poll, Futakuchi placed 16th with 1,592 votes. In the second, he dropped to 23rd with 2,218 votes.
- Kenji (堅治) - To govern firmly
- Futakuchi (二口) - Two mouths
- "Sure~ Sorry about that. This guy [Aone] targets our opponent's ace whenever he sees them. So... you better be ready." (To Karasuno High, Season 1, Episode 15)
- "Hey, what was that? He's supposed to get dejected." (about Asahi, Season 1, Episode 17)
- "I was selfish, so I'm sure my senpais had a hard time with me, but I have to wonder about being too serious, too." (To Aone about Koganegawa, Season 2, Episode 19)
- "Look, you don't have to feint when you do a dump attack. Smash it!" (To Koganegawa, Season 2, Episode 19)
- "All right, let's go. The fact that you guys are here means that you have time on your hands, right? Come back and practice with us." (To Date Tech's third-years, Season 2, Episode 19)
- "Positions and such don't matter once you're on the court." (To Oikawa, Season 2, Episode 18)