Review:
I'll start by saying that the description on the back of the volume contains several incorrect statements. There is no evidence that Souji's sisters' clingy behavior is anything new. Also, I don't know if Souji and Yukako start dating in the next volume, but Yukako is not Souji's new girlfriend in this one. Now, on to my description.
Souji is a high school student who left his family home some time ago. He had hoped never to return, but sometimes we don't get what we want. At any rate, his three sisters are thrilled he's back. Harumi, his stepsister, is sweet and quiet and clearly has a crush on him. The real problems, though, are Youko and Saki. Youko is Souji's full sister. She possibly has a split personality, and she's certainly a vaguely malevolent presence in the household, glaring daggers at Souji even as she cuddles up to him in a more than sisterly sort of way. Saki is the daughter of Souji's father and Souji's father's mistress. She works as one of the family's maids and, when the other sisters aren't around, sleeps with Souji. And possibly also Kazushi, Souji's older brother. Kazushi, meanwhile, may be lurking somewhere nearby.
At school, Souji instantly comes to the attention of Yukako, the self-proclaimed sole member of the student council's “Intelligence Committee.” It's Yukako who tells Souji of the three murders that occurred at the end of the summer, shortly before he arrived. The school's smartest student was stabbed. After that came the track team's star runner, also stabbed. Then the student council president was pushed in front of a train. Yukako wants to know why the killer chose those particular victims, especially since she had a crush on the student council president. She basically forces Souji to join her, but Souji secretly thinks he knows who was responsible: Youko, his sister.
