Diamond no Ace Wiki
Masuko Tōru
Seidou High School - No. 5
Third Baseman
Bats: Right Throws: Right
Kanji 増子 透
Gender Male
Age 17 (debut)

18 [1]

Date of birth 14 October
Place of birth Tokyo
Bloodtype O
Height 182 cm (5' 11.5")
Weight 82 kg (180 lbs)
Education 3rd Year High School (debut)

Seidou Alumnus [2]

Class 3-B
Skills super heavyweight power hitter
First Appearance
Manga Act I - Chapter 4
Anime S1 - Episode 3
Voice Actor Wataru Hatano
Masuko ...
Did you get fatter?
Coach Kataoka during the 3rd-Years's retirement game [3]

Masuko Tooru was the vice-captain and third baseman of the Seidou High School, also the former roommate of Sawamura Eijun and Kuramochi Youichi. After his retirement, he was the roommate of Takigawa Chris Yuu and Makihara.


Masuko does not talk much. But when he is talking, he says the most important in the shortest way. He is kind by nature, so he is bulled by his kouhais[4] sometimes.

He is very strict with himself. He bans himself from speaking after making an error in a match - as seen at Masuko and Sawamura's first meeting[5], when he only communicated by writing notes. Kuramochi told Sawamura later, that Masuko had made a mistake the other day and now does not let himself talk.

Because of his purposefulness, which shows itself in his avid training, he seems solid as a rock. Thanks to this purposefulness he gets permission from coach Kataoka to return to the starting lineup. He is very good at hitting fastballs but bad with breaking balls. Despite his large physique he moves fast. He was the team's fifth batter (also called five-hole[6]).

Player Statistics[]

This data is based on the official guidebook, it will only be changed if there is an official update!

Player Statistics
Note that just because a character said something about another characters improvements is not considered an official update!
You are free to write about the characters improvements in the Skills section above!
Physical Strength
Mental Strength



  • At the start of his 3rd Year, he lost his position on the starting lineup because he made an error during a match. [5]
  • His hobby is pudding tasting. [7]
  • His family's liquor shop will be turned into a convenience store in the near future.
  • When he came to watch Seidou vs. Sousei game in Act II, he has slimmed down 20% from what he were back in the Fall season of previous year according to himself. [8]
  • Rankings from the guidebook:[7]
    • Physical Ability: He ranks second in Back strength, behind Nagata Shouhei from Seiko.
    • Batting: He ranks fifth in having the best batting power.
  • He was in the same class (3B) as Isashiki Jun and Kominato Ryosuke.
  • Favorite Food: Rice and Pudding[7]
  • Favorite Subject: World History[7]
  • Person he respects: Coach Kataoka[7]
  • His family's convenience store is called Fairy Man.[9]
  • He attended Ouura Junior High in Saitama.
  • He shares a birthday with Toujou Hideaki.
  • Sawamura gave him his nickname MVP.


  • “If the ball had been off by a little bit, the one who would have lost was me. It was a good ball, full of spirit, Sawamura-chan.” - about Sawamura[10]



  1. Act I - Chapter 298
  2. Act I - Chapter 412
  3. Act I - Chapter 230
  4. Senpai (先輩) and kōhai (後輩) are terms applied to the mentor system in wide use in Japanese culture; often found at all levels of education, in sports clubs, businesses, and informal or social organizations. The senpai is roughly equivalent to the Western concept of a mentor, while kōhai is roughly equivalent to protégé, though they do not imply as strong a relationship as these words mean in the West. More simply, these may be translated as senior and junior.
  5. 5.0 5.1 Act I - Chapter 4
  6. In modern American baseball, some batting positions have nicknames like "leadoff" for first, "cleanup" for fourth, and "last" for ninth. Others are known by the ordinal numbers or the term #-hole (3rd place hitter would be 3-hole).
  7. 7.0 7.1 7.2 7.3 7.4 Official Guide Book - Omote
  8. Act II - Chapter 204
  9. Act I - Epilogue 3 "Brand New Day"
  10. Act I - Chapter 16
  11. This mistake happened the day before their match against Sensen High School in chapter 123.