Ryoko, a married woman who returned to her alma mater for the first time in five years as a substitute for a senior teacher who was on maternity leave. There, she meets Ichikawa, a former student who works as her teacher after graduating. Ichikawa, who has admired Ryoko for a long time, can't help but hit her feelings while warming up to her old friendship. Ryoko, who is overwhelmed by her momentum, forgives her, saying, "If it's just a kiss," but her student Hashimoto finds out! As a secret exchange condition, Hashimoto said, "Let me do the same thing as him."
