Seiou Senior 静央シニア
Represents Shizuoka.
Year 1:
- Total of 76 members.
- Made it to quarterfinals for Kantou Summer Tournament.
- Made it to semifinals for the National Tournament.
Year 3:
- Around 60 members.
- Made it to quarterfinals for Kantou Summer Tournament.
Staff
Kantoku: Noda Akio 野田明雄

- First Appearance: Volume 1, Chapter 1
Coach: Matsumaru Yousuke 松丸洋介

- First Introduced: Volume 1, Chapter 13
Players
Ayukawa Eita 鮎川瑛太

First Introduced: Volume 5, Chapter 40 (first-year student)
Younger brother to Ayukawa Satoshi
- Attending: Seinan Middle School (静南中学校)
- Throw Left, Bats Left.
- Year 1 (first-year student):
- Team A
- Batting Order: 8th
- Year 2 (second-year student):
- Team A, Number #9 (Spring) → Number #1 (Summer)
- Position: Pitcher (reserve → ace)
- Year 3 (third-year student):
- Team A, Number #1
- Position: Pitcher (ace)
- Batting Order: 3rd, 6th
- Accepted sports scholarship to Shouzaidaifuzoku High School.
Ayukawa Satoshi 鮎川智

First Appearance: Volume 1, Chapter 2 (third-year student)
First Introduced: Volume 2, Chapter 12 (third-year student)
Older brother to Ayukawa Eita
- Attended: Seinan Middle School (静南中学校)
- Throw Right, Bats Right
- Year 1 (third-year student):
- Team A
- Position: Catcher
- Batting Order: 4th
- Year 2-3 (alumni):
- Currently studying at Kousei High School.
Ekoda 江古田
- First Appearance: Volume 13, Chapter 118
- Year 3:
- Team B
- Position: Shortstop
- Batting Order: 5th
Funaki 船木
- First Mentioned: Volume 11, Chapter??
- First Appearance: Volume 16, Chapter 150 (second-year student)
- Year 3 (second-year student):
- Team B -> Team A (Summer)
Hakamada Hiroshi 袴田浩

First Introduced: Volume 2, Chapter 12 (first-year student)
- Attending: Sakuranomiya Middle School (桜ノ宮中学校)
- Throw Right, Bats Left
- Year 1 (first-year student):
- Team B
- Position: Shortstop / Catcher
- Year 3 (third-year student):
- Team Captain and Team A, Number #2.
- Position: Catcher
- Batting Order: 1st
- Accepted sports scholarship to Yokohama Daiichi High School but is considering to retract in Volume 13, Chapter 133.
Higashide 東出
- First Introduced: Volume 2, Chapter 17
- Year 1:
- Second year
- Team B
- Position: Center
Higashi Nagasaki 東長崎
- First Mention: Volume 11, Chapter 107
- Year 3:
- Team B
- Batting Order: 4th
Ishihama Bungo 石浜文吾

First Appearance: Volume 1, Chapter 1 (first-year student)
- School: 桜ノ宮中学校 Sakuranomiya Middle School
- Throw Left, Bats Right
- Year 1 (first-year student):
- Team A, Number #25
- Position: Pitcher (reserve).
- Year 2 (second-year student):
- Team A, Number #20
- Position: Pitcher (reserve).
- Year 3 (third-year student):
- Team A, Number #14→#10→#9 (Summer)→#1 (Nationals)
- Position: Pitcher (reserve) → Pitcher (ace).
- Has received over 50 sport scholarship offers but has yet to formally accept one.
Ishigami 石神

- First Appearance: Volume 14, Chapter 132
- Year 3 (second-year student):
- Team B
- Position: Pitcher (reserve).
Kakitani Yuzuru 柿谷結弦

First Mentioned: Volume 1, Chapter 7
First Appearance: Volume 6, Chapter 65 (third-year student)
- Year 1 (third-year student):
- Team Captain.
- Member of Team A, but not active until after Kantou Summer Tournament.
- Position: Outfielder
- Year 2-3 (alumni):
- Currently studying at Aomori Sanada High School.
Kamiya Makoto 神谷真琴

First Appearance: Volume 1, Chapter 2 (first year)
First Introduced: Volume 1, Chapter 3 (first year)
- Attending: Sakuranomiya Middle School (桜ノ宮中学校)
- Throw Right, Bats Right
- Year 1:
- Team A
- Position: Second Baseman
- Batting Order: 2nd
- Year 3 (third-year student):
- Team A. Number #4.
- Position: Second Baseman
- Batting Order: 2nd
Kimura 木村

- First Introduced: Volume 2, Chapter 13
- Throw Left
- Year 1 (second-year student):
- Team B
- Position: Pitcher
- Year 2 (third-year student):
- Team A, Number #1
- Position: Pitcher (Ace).
Koyano Ken 小谷野兼

First Introduced: Volume 10, Chapter 93 (first-year student)
- School: Seihoku Middle School (静北中学校)
- Throw Right, Bats Left
- Year 3 (first-year student):
- Team A. Number #6→#5 (Summer).
- Batting Order: 9th.
Mase Kazuo 間瀬和夫
First Introduced: Volume 9, Chapter 80 (third-year student)
- School: Seikou Middle School (静光第二中学校)
- Year 3 (third-year student):
- Team A. Number #8.
- Position: Center
- Batting Order: 3rd.
- Accepted sports scholarship to Kousei High School.
Mizushima Hiroto 水島廣人
First Appearance: Volume 1, Chapter 2
First Introduced: Volume 1, Chapter 4
- Throw Right, Bats Left
- Year 1 (third-year student):
- Team A
- Position: Third Baseman
- Batting Order: 1st
- Year 2-3 (alumni):
- Currently studying at Yokohama Daiichi High School.
Nishio 西尾
- First Introduced: Volume 2, Chapter 17
- Year 1:
- Second year
- Team B
- Position: Right
Noda Yukio 野田幸雄

First Appearance: Volume 1, Chapter 1 (first-year student)
Former member of the U-12 Japan Representative team.
Currently, a member of the U-15 Japan Representative team.
- Attending: Sakuranomiya Middle School (桜ノ宮中学校)
- Throw Right, Bats Right.
- Year 1 (first-year student):
- Member of Team A.
- Position: Shortstop.
- Batting Order: 5th
- Year 3 (third-year student):
- Member of Team A. Number #6.
- Position: Shortstop.
- Batting Order: 4th.
- Has received over 100 sport scholarship offers but has yet to formally accept one.
Ono Hiroaki 尾野博明
First Introduced: Volume 10, Chapter 93 (first-year student)
- Throw Right, Bats Right
- Attending: Seihoku Middle School (静北中学校)
- Year 3 (first-year student):
- Team A. Number #7.
- Position: Left
- Batting Order: 8th.
Satou 佐藤
- First Introduced: Volume 2, Chapter 13
- Year 1:
- Third-year.
- Team A
- Position: Pitcher (reserve)
Shinoda 篠田
- First Appearance: Volume 13, Chapter 118
- Year 3:
- Team B
- Position: Right outfielder
- Batting Order: 8th
Shinsako Takumi 新迫拓巳

First introduced: Volume 25, Chapter 244
- Year 3: Third-year.
Suzuki 鈴木
- First Introduced: Volume 2, Chapter 13
- Year 1:
- Third-year.
- Team A
- Position: Pitcher (reserve)
Toyoda Kentarou 豊田健太郎

First Appearance: Volume 3, Chapter 25
First Introduced: Volume 4, Chapter 30
- Year 1 (alumni):
- Former ace pitcher of Seiou (who lead the team to SF in the Nationals) and a mentor (2 years older) to Yoshimi.
- Year 3 (alumni):
- Graduated from Shouzaidaifuzoku-Shouzai High School. Now playing baseball in college.
Watanabe 渡辺
- First Introduced: Volume 2, Chapter 13
- Year 1:
- First-year.
- Team B
- Position: Pitcher
Yokoyama Tooru 横山徹

First introduced: Volume 25, Chapter 244
- Year 3: Third-year.
Yonemura Takaho 米村高穂

First Introduced: Volume 11, Chapter 100 (first-year student)
- Attending: Seikou Middle School (静光中学校)
- Throw Right, Bats Right
- Year 3 (first-year student):
- Team A. Number #12 (Summer).
- Position: Catcher (reserve)
- Batting Order: 7th
Yoshimi Masaki 吉見雅樹

First Mentioned: Volume 1, Chapter 7
First Introduced: Volume 2, Chapter 12 (third-year student)
- Attended Sakuranomiya Middle School (桜ノ宮中学校).
- Throw Right, Bats Right
- Year 0 (second-year student):
- Member of Team A. Number #1
- Position: Pitcher (Ace)
- Year 1 (third-year student):
- Member of Team A. Number #1
- Position: Pitcher (Ace)
- Batting Order: 3rd
- Year 2-3 (alumni):
- Currently studying at Shouzaidaifuzoku-Shouzai High School.