Diamond no Ace Wiki
Ochiai Hiromitsu
Seidou High School
Bats: - Throws: -
Kanji 落合 博光
Nickname Sergeant (軍曹 Gunsō) (by Sawamura)
Gender Male
Age unknown
Date of birth 3 March
Place of birth Kanagawa
Bloodtype B
Height 174 cm
Weight 70 kg
Education unknown
First Appearance
Manga Act I - Chapter 203
Anime S1 - Episode 66
Voice Actor Ookawa Tooru
Athletes are all masochists and narcissists.
Ochiai in Outsider

Ochiai Hiromitsu is the assistant coach. [1] of the Seidou High School Baseball Team.


He has a radical, straightforward way to lead a team. If he were the coach he would limit the number to twenty people from each school year and prohibit ordinary guys to join the team unless they show an outstanding talent, because he thinks that the team has way too many members. [2] and he would prefer it to spent his time only on improving the elite few players.

"It may be just high school baseball, but it's still all about skills and results. There's no time to waste it on those who have no chance to grow into good players."

Ochiai often gives the impression of being arrogant and smug. He is seen more than once thinking that his time to take over the team is fast approaching.

Because Ochiai doesn't share the same view as Kataoka, he often appears out of nowhere – which is kind of creepy sometimes - when the coach is not around, to talk to one or two players alone, so that nobody gets in his way.


In the past, he was an assistant coach of the baseball club/team in Kokai University Sagara High School from Kanagawa, a team that regularly appeared at Koshien. [3]

Relationships with other characters

Furuya Satoru

Right from the beginning Ochiai sees great potential in Furuya. He would prefer it, if Kataoka would let Furuya pitch a whole game, so that Furuya could gain more game experience. He also suggested they sacrifice the team solely for Furuya and his growth. [4] Kataoka argues that he perfectly understands the importance of having the ace, but isn’t willing to sacrifice one of the very few ways for the team to get to Koshien for just Furuya.

Sawamura Eijun

Because Sawamura can’t throw inside pitches after his match against Inashiro (because of the yips) Ochiai thinks he can't be used - although he admits that his pitches aren't half bad. To use Sawamura nonetheless he suggests Sawamura switch to being a sidearm pitcher to let Seidou's batters practice against him for the upcoming match, because the pitcher of their next opposing team is a left-handed sidearm pitcher. That way Sawamura will be useful to the team. The moment in which Kataoka finds out, he orders Sawamura to stop immediately, because it would destroy his form. [5] He only cuts Ochiai a look, but says nothing. Later in the series, he helped Sawamura to learn breaking balls and develop the Change-up and Palm ball, admitting that he has potential to become a good pitcher.

Kataoka Tesshin

Kataoka and Ochiai disagree.

At the beginning he often confronts Kataoka with the fact that as long as Furuya is on the team, Sawamura will always be number two, no matter how hard the later works. But Kataoka stated that he never would sacrifice the whole team solely for Furuya, unlike Ochiai. Ochiai is curious about Kataoka and wants to know how good he can be at being a coach. He often states that Kataoka is pushing the players hard during training sessions and calls him "Devil". [6] Although they disagree from time to time Kataoka values Ochiai’s opinion as a coach and vice versa.


  • He is shy to strangers. [6]
  • Ochiai has a five-year old daughter. [7]
  • He has a twitter that he often updates.
  • When he was in high school, he played baseball as one of his team's catchers, but was not a starter. [8]


  • "But you lost. It's like you are practicing just to lose." - to 1st-Year trio [3]
  • "Damn! What's with that old guy! He talks all nasty!" - Sawamura [3]
  • "This pitcher is useless." - about Sawamura [9]
  • "Even from an objective standpoint this team isn't weak. The players are highly motivated and the atmosphere during practice isn't bad. Surely all the players are well-trained under Kataoka-san's guidance. But it's hard for the current team to dominate in the fall tournament." - to Kataoka [4]
  • "This fall is a joint suicide with Furuya." - to Kataoka [4]
  • "In other words, Sawamura is a stalking horse needed to bring out Furuya's full power."- to Kataoka, Takashima, and Oota[10]
  • "We all know, and especially you, coach Kataoka, that as long as there's Furuya on this team, Sawamura will always be number 2, no matter how hard he works." - to Kataoka, Takashima, and Oota [10]
  • "He became the master of the bullpen before we knew it." - Oota [11]
  • "With much desirable things comes also many undesirable things. To soar even higher, an even more unshakable foundation will be needed." - to Takashima [12]



  1. While both can be called coach in English, Kataoka is 監督 ‘kantoku’ (the main coach) and Ochiai is コーチ(simply coach/trainer)
  2. At that moment the team has 59 members, but he assumes that the number will surpass 100 after the new first years will join
  3. 3.0 3.1 3.2 Act I - Chapter 204
  4. 4.0 4.1 4.2 Act I - Chapter 223
  5. Act I - Chapter 239
  6. 6.0 6.1 Act I - Chapter 205
  7. Act I - Chapter 412
  8. Act II - Chapter 49
  9. Act I - Chapter 222
  10. 10.0 10.1 Act I - Chapter 292
  11. Act I - Chapter 318
  12. Act II - Chapter 10