As his family takes off for a few days, Seiji finds himself home alone. Well, except for Guri, of course. But the peace of the moment is short-lived when Akane shows up at his door saying she's there to spend the night while his family is away and to claim the kiss that Seiji had promised her. Things only get more complicated as usual when Yuzu and Shikimi show up as well. Things seem to go rather okay until Seiji's younger sister Akua returns home early to find Seiji surrounded by all four girls in a compromising situation and proceeds to scold her brother for his behavior. Curious about the siblings' relationship, Guri drags Akua out shopping to get to the bottom of her brother-complex.
You're always messing around, so it made 
me wonder if you really liked him!
Da du die ganze Zeit mit ihm rumspielst,
kam ich auf den Trichter.
¡Como siempre haces el tonto,
dudé de si te gustaba realmente!
¡Como siempre haces el tonto,
dudé de si te gustaba realmente!
C’est peut-être parce que
tu ne prends rien au sérieux !
Scherzi sempre, per cui mi viene il dubbio
che non ti piaccia davvero!
Você sempre fica de brincadeira, então
 não sabia se gostava mesmo ou não!
Ты всегда дурачишься, и поэтому
я не понимаю, нравится он тебе или нет!