After another loss, Rina grows frustrated with Mai's carefree attitude and considers quitting. Mai proposes finding fun for everyone, leading to a bowling challenge.
Mai and friends are sent to the Sengoku era, reunite with Rina, and escape a bandit attack with help from Suguri who's then captured. They set off to rescue him, balls in hand.
At Suguri's mansion, Mai and friends meet two princesses. Suspecting they might vanish if they alter history, they search for a way home. Meanwhile, one of the princesses, Sumomo invites Mai to play bowl and then says something unexpected.
Rina asks, "Why don't you want to win?" Mai responds with a string of questions: "Why do you want it so badly? Why can't it just be fun? Why do you always end up alone?" The fourth throw marks both an end and a beginning.
