Brothers Aki and Shima are upset by the sudden appearance of a "fourth brother" in the Kaidou family, and Haru's excessively affectionate attitude towards Ren makes Aki explode with rage. Meanwhile, Haru happens to witness a car accident in the city. Since then, Haru begins leaving Ren alone in the apartment. On top of that, while Ren is home alone, one of Haru's customers from the host club forces her way into the apartment, and--?!
After all, I've never felt 
that way about my sister.
Ich habe meine Schwester
ja auch nicht gemocht.
Después de todo, 
yo nunca quise a mi hermana.
Después de todo, 
yo nunca quise a mi hermana.
Moi,
Dopotutto, neanch'io ho mai
voluto bene a mia sorella.
Afinal, eu nunca gostei da minha irmã mais nova.