Diamond no Ace Wiki
Akamatsu Shinji
Akamatsu shinji
Inashiro Industrial - No. 18
Bats: Throws: Right [1]
Kanji 赤松 晋二
Gender Male
Age 15 (debut)
Date of birth 15 November
Education 3rd Year Junior High (debut)

1st Year High School (current)

Skills Curveball
First Appearance
Manga Act I - Chapter 378
Anime S2 - Episode 43
Voice Actor Yonaga Tsubasa

Akamatsu Shinji (赤松 晋二) is a student of Inashiro Industrial. He was a third year student of Ritsurin Junior High and ace of Minamisawa Senior (League).


Akamatsu has short-messy light brown hair and brown eyes. He is tall in height and always has a smile on his face.

Act I[]

Fall Tournament[]

Akamatsu watched the finals match between Seidou High and Yakushi High. He meets his fellow middle school students Yuuki, Okumura, and Seto then asks them what High School they will enroll to. While the three of them decided to go to Seidou, Akamatsu is going to Inashiro, saying that he looks forward to facing them in the future.[1]

He goes to meet Tadano and the latter comments on how tall he's become. He offers to help Tadano with the bags Tadano carries but Tadano declines, explaining that it's a punishment. He talks to Narumiya, saying that he can't wait to play with the pitcher he respect so much. Narumiya tells him that he is well-mannered then asks his name.

After the match, he is seen talking to Okumura and Seto.[2]

Act II[]

Spring Tournament[]

Akamatsu is currently a freshman at Inashiro Industrial. During Inashiro's third round match against Yakushi High at the Spring Tournament, while some of his teammates express concern over Yakushi's relaxed demeanor before the match, Akamatsu expresses confidence in Inashiro's roster saying that when the match begins, it'll become clear just who are the kings.[3]

Following Inashiro's victory, Akatmatsu and his teammates Shima Ryouhei, Yoshizawa Akimitsu, Mitsuichi Youji bumps into some of Yakushi's freshmen players. Akamatsu recognizes Tomobe Sakito who tells Akamatsu that they will win next time their teams play on the field. Akamatsu replies hoping next time, they face each other on the field.[4]

He soon makes it to the first string, and sits with them on the bleachers watching Teito High and Ugumori High's match.[5]

Kanto Tournament[]

Akamatsu played his first official high school match in the Kanto Tournament. Sent into the mound in the 6th inning of the 3rd round match against Hokushin Academy, he looked unbelievably calm in his debut and at 1 out, he scored 6 consecutive Strike outs to close out the match for Inajitsu.[6]


Tadano Itsuki[]

Akamatsu and Tadano played on the same team together in the past. Akamatsu appears to admire Tadano and looks forward to playing with him again.


Akamatsu comes off as a calm pitcher. He is able to throw in the upper 130 kph and has Drop Curveball with unique movement.


  • Akamatsu scored 6 consecutive Strike-outs in his debut match in the Kanto Tournament, a feat similar to what Furuya did in his debut match.

Name Etymology[]

  • Akamatsu (赤松) - Japanese Red Pine
  • Shinji (晋ニ) - Advancing Second






  1. 1.0 1.1 Act I - Chapter 379
  2. Act I - Chapter 411
  3. Act II - Chapter 15
  4. Act II - Chapter 20
  5. Act II - Chapter 24
  6. Act II - Chapter 90