Ami and Sumire were childhood friends. However, after they drifted apart, they reunited at the same school, where Ami had become a delinquent gal who was rumored to be involved with gangsters and taking drugs. Meanwhile, Sumire started dating a boy, but Ami immediately began bullying him. In fact, Amiri had distanced herself from Ami and gone astray in order to give up on her unrequited love for Sumire. Ami could no longer bear Sumire repeatedly blaming herself in order to protect her boyfriend, so she tried to ruin everything with a back-channel aphrodisiac.