At the bowling club of Ikkokukan High School in Nagano Prefecture, Mai, the club captain, prioritizes everyone's enjoyment over winning. However, her passionate junior, Rina, declares, I want to win. When Rina threatens to quit the club, Mai tries to convince her to stay, but Rina challenges her to a match and says she'll only remain if Mai wins. As the game begins, the bowling ball suddenly starts to glow, and all five club members are engulfed in a mysterious light. When they awaken... they find themselves transported to none other than the Warring States period! (Source: Official site, translated)