4 ideas
In a Tokyo suburb one summer, a high-school boy nicknamed Worm kills his mother and flees on the bicycle and mobile phone he takes from Toshi, the girl next door. Instead of going to the police, Toshi and her friends Yuzan, Terauchi and Kirarin each help or join him by phone and in person, and the episode ends in deaths among the group.
Each sees in his act a version of her own unspoken resentment of parents, school and expectation. Aiding him becomes a way to act out that grievance vicariously. Moral lines are crossed through projection, not persuasion, which is why none of them feels she has decided anything.
Told in alternating first-person voices, the book shows each girl keeping a public persona for parents and friends and a concealed inner life: a secret sexuality, a double social life, a hidden contempt. Friends who think they know each other are actually trading masks, so real intimacy is rarer than it looks. Read this way, the question is not who a teenager is but how wide the gap is between her two selves.
Because the girls deal with the fugitive mostly through a borrowed mobile phone, his murder stays abstract, closer to a game or a story than an act with a victim. The mediated distance lets them feel involved without feeling responsible. Consequences become real only when bodies and deaths intrude on the conversation.