The Sun Shine Brightly on the Solitary Island - S1.E5

The C3 Club travels to a remote island for a practice match against the Seto Family team from Kansai, which they manage to win thanks to Yura's quick thinking. After the match, they spend the rest of the evening having a barbecue and setting off fireworks. Later that night, Yura has a nightmare about falling back to her old self and becomes determined to win the next match. The next morning, when everyone's flags are accidentally burned, they decide to have a Capture the Center Flag match using bikini tops instead. As the match gets underway, Sonora notices Yura is a bit more fired up than usual whilst the other members struggle due to the Seto team's strategy of using dual weapons to confuse their numbers. With Yura's help, the C3 Club manage to overcome the Seto team's strategy and win the match, though Sonora does not seem happy about it.