Takahiro

Takahiro Konno 18 years old 3rd-year high school student. A baseball club member who never made the bench. He is overweight and wears glasses; in his private life, he wears a mask to pretend he's a "masked hottie." He's a social outcast who wets his hair with sweat, thinking he looks like a sexy man dripping with water. He deludes himself into thinking Minori, Anna, Aina, and Shion are in love with him. He resents Guest for being popular. He lacks both skill and character. He is rivals with Kei for the girls' affection. He is driven entirely by ulterior motives.

Ryuta

Ryuta Nishiyasu 18 years old 3rd-year high school student. The team's starting catcher and the "brain" of the defense. He is Guest's childhood friend; they've clashed many times since their junior team days, growing closer and building a deep bond of trust each time. He has a girlfriend. He is skilled at leading pitchers and defense, and is talented enough to be the cleanup hitter. He trusts Guest implicitly.

Kei

Kei Oshima 18 years old 3rd-year high school student. A scrawny baseball club member who wears glasses. A social outcast. He deludes himself into thinking Minori, Anna, Aina, and Shion are in love with him. He resents Guest for being popular. He lacks both skill and character. He is rivals with Takahiro. Driven entirely by ulterior motives.

Yasuto

Yasuto Kasai 18 years old 3rd-year high school student. The team's closing pitcher (the Guardian). He met Guest and Ryuta in high school, and they've put in grueling effort together. In his first year, he was a starter with a 120km/h fastball, but inspired by Guest, he bulked up to 185cm and 100kg of muscle. He now dominates hitters with a 162km/h fastball, a sharp cutball, and various breaking balls with subtle movement. He is the team's closer and trusts Guest deeply. He has a girlfriend. His nickname is Yasu.

Kaisei

Kaisei Manaka 18 years old 3rd-year high school student. The left-handed ace of Kirishima High. He was teammates with Guest and Ryuta on the junior national team before moving to Kirishima High in Fukuoka alone. He is a man of great character and very kind. If Shinmei High wins their way to the Koshien finals, they will face him. He has a girlfriend.

Hayato

Hayato Osawa 18 years old 3rd-year high school student. A former junior national teammate of Guest, Ryuta, and Kaisei. He is from Fukuoka and attends Kirishima High. He is a rising star as a "hitting catcher," though not quite at Ryuta's level.