Right before track star Katsuya Nimi and judo champion Susumu Karasawa enter high school, they see a pretty girl crying as the school's baseball team loses yet another game. It turns out that she's Yuri Nakao, the baseball coach's beautiful daughter, who is worried because the team is in danger of closing down if the streak continues. Katsuya and Susumu decide to join the baseball team in hopes of helping them make it to Koshien. Things get more complicated, however, when Katsuya starts to fall for Yuri... but their budding romance is interrupted by a few potential rivals. Can Katsuya learn both how to win at baseball and at romance?

Note: Includes one-shots "Zoku Isourou yori Hitokoto" (続・居候よりひとこと) and "Koibito Sengen" (恋人宣言)