(from ebookjapan):

The captain of the baseball team, Tatsushi Fuyoshi, is summoned to the principal's office, where he is suddenly ordered by the principal to discontinue the baseball team, declaring that the club must "win Koushien" in order to survive, and as proof of his determination, he vows to defeat Hinode Shogyo, the 8th best team from spring Koushien , in a practice game in 10 days' time.

The nine members start training hard that day, but three days before the game, one by one, they start to drop out...?