Freed from her boyfriend and hopelessly hooked, Rina refuses to let their “one time” be the end, and she and Naoto slip into a secret affair right under Koto’s nose. She swears each encounter is the last, torn by guilt toward her best friend, yet Naoto keeps her utterly addicted to him. Their luck runs thin when another classmate, Mashiro, meets Naoto and starts to suspect he’s the mysterious “older man” Rina has fallen for.