|Seidou High School - No. 1|
|Bats: Right||Throws: Right|
|Age||18 (debut) |
|Date of birth||10 April|
|Place of birth||Tokyo|
|Height||185 cm (6' 1")|
|Weight||77 kg (169 lbs)|
|Education||3rd Year High School (debut)|
Seidou Alumnus 
|Skills||140 km/h Fastball|
|Manga||Act I - Chapter 8|
|Anime||S1 - Episode 4|
|Voice Actor||Masakazu Morita|
|“||You are the ace from here on. Pitch with that in mind.||”|
— Tanba to Sawamura in Decision
Tanba Kouichiro was the ace pitcher of the Seidou High School baseball club. He applied for one tryout and despite not having high hopes of passing, he passed the tryout.
In his first year he was really shy and it took him three years to understand how a real ace must be. Because of injuries, he had withdrawn from the front lines again and again. For that reason he’s thirsting for a chance to pitch and has a strong attachment to the mound. Finally in his last year of high school, he gains the trust of the coach and the whole team and becomes the ace. But being the starting pitcher and the ace of a school which is famous for baseball often brings him a lot of stress.
He’s too serious and quiet, people tend to think he is blunt but in reality he’s extremely considerate to friends. He has a passionate side to him when he gave a roar of triumph on the mound after getting the batter out at the critical moment.
Relationship with other CharactersEdit
Sawamura and Furuya are the freshmen who had threatened Tanba for the ace position, and fired him up to enhance his pitching and develop his forkball. As the ace, he realized his role to inspire and challenge his fellow pitchers without letting them overshadow him.
He resents Miyuki's straightforward conversation with him regarding his pitching skills. However, knowing Tanba had to work with him on important games, he has no choice but to work with him and respond to his calls. They do well as battery despite their difference and both respect each others abilities as they pair up longer.
Chris is the catcher who Tanba wants to form a battery with before they graduate. However, he never had a chance to pitch for him because as soon as he earned his place, Chris was forced to retire due to an injury. Chris noticed an injury that could have affected the course of Tanba's high school career. He was able to successfully recover from it and resume pitching as the teams ace. Tanba has great respect for Chris and expresses his appreciation for his action and concerns. His greatest wish for Chris is his full recovery from his shoulder injury and his return to the first-string team for their final year.
Tanba and Manaka are good friends who grew up playing baseball together and both played the pitcher position. In Junior High, Tanba tells Manaka that he'll be going to Seidou High wanting to change himself, and not to continually walk in Manaka's shadow. When they graduate from middle school, they promise each other to become aces of their teams and fight it out at Koshien.
|“||You're a much better pitcher than you give yourself credit for.||”|
Tanba hurt his arm in autumn of his second year in high school, and returned to the team in Spring of his third year. After his return, he learned how to throw a powerful curveball which is his best weapon.
- Favorite food: Seafood 
- Best Subject: Modern National Language
- Hobby: Reading (Personal development books)
- Favorite books: Okamoto Tarou "Tarou ni Kike!" series 
- He has respect for Kuwata Masumi.
- Rankings from the guidebook:
- The break of his breaking balls ranks third.
- He ranks fifth at Fielding.
- The speed of his pitches ranks fifth.
- Seidou Baseball Club secret rankings:
- Tanba has the third cleanest room.
- When it comes to skillful singing, Tanba ranks first. His best performance is the song "Yell” by Kobukuro.
- Being the starting pitcher for a school famous for its baseball club often brings him a lot of stress. 
- He wants to repay the coach for recommending he play a match in his 1st-Year. 
- In the Fall of his 2nd-year, he injured his arm and only returned the club/team at the start of his 3rd-Year. 
- "Even though he is blessed with a good physique, he is delicate. I wonder if there were a lot of people where were worried (laughes)" - Kominato Ryousuke 
|Seidou High School|
|Miyuki Kazuya • Maezono Kenta • Kuramochi Yōichi • Kawakami Norifumi • Asou Takeru • Nakata Ataru • Ono Hiroshi • Higasa Shōji • Seki Naomichi • Yamaguchi Ken • Kijima Rei • Kawashima Kengo|
|Sawamura Eijun• Furuya Satoru • Kominato Haruichi • Kanemaru Shinji • Tōjō Hideaki • Kaneda Tadahiro|
|Yui Kaoru • Yūki Masashi • Okumura Kōshū • Mogami Takeshi • Asada Hirofumi • Seto Takuma • Kuki Yōhei
|Former players||Yūki Tetsuya • Tanba Kōichirō • Kominato Ryōsuke • Masuko Tōru • Isashiki Jun • Miyauchi Keisuke • Sakai Ichirō • Kadota Masaaki • Kusunoki Fumiya • Takigawa Chris Yū • Azuma Kiyokuni
|Managers||Fujiwara Takako • Umemoto Sachiko • Natsukawa Yui • Yoshikawa Haruno
|Staff||Kataoka Tesshin • Ochiai Hiromitsu • Takashima Rei • Kazuyoshi Oota|