Summer vacation! Seiji, Guri, Akane and Yuzu have invited Akua to go with them to the beach. Akane tries to get Akua to go swimming with her in attempt to get closer to Seiji's little sister, but Akua gives her the cold shoulder. Pouting at her brother and his harem Akua goes to swim by herself but a dark shadow looms beneath her. Meanwhile, summer also means tests of courage! Guri suddenly invites Seiji, Akane, and Yuzu to the school after dark for a test of courage but her real motives are to pair another young couple who have asked for her help. Seiji thinks something isn't quite right about the pair though...
Th-There's no other choice, so I'll let you 
carry me until we meet up with Onee-sama.
W-Wenn du mir
keine Wahl lässt,
Qué remedio,
dejaré que me lleves con mi hermana.
Qué remedio,
dejaré que me lleves con mi hermana.
Fort bien, je t’autorise à me porter
jusqu’à ce qu’on retrouve Akane.
Visto che non c'è altra scelta, ti permetto
di portarmi finché non incontriamo Oneesama!
N-Não tenho escolha, eu deixo que me 
carregue até encontrarmos minha irmã.
Но раз другого выхода нет, так и быть, 
я позволю тебе отнести меня к сестре.