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.
Well, I'll be sleeping in the living room,
so call me if you need anything.
Okay, ich werde im Wohnzimmer schlafen,
ruft mich, wenn es euch an irgendetwas fehlt.
Bueno, yo dormiré en el salón,
llámenme si necesitan algo.
Bueno, yo dormiré en el salón,
llamadme si necesitáis algo.
Je vais dormir dans le salon,
appelez-moi si besoin.
Beh, io dormo in salotto,
chiamatemi se avete bisogno di qualsiasi cosa.
Bom, eu vou dormir na sala.
 Qualquer coisa, me chamem.
Я буду спать в гостиной. 
Если будет что-то нужно, дайте знать.