Tsubomi is a member of the swimming club and spends her days practicing every day. - Natsume, a beautiful teacher who works as an advisor for the swimming club, is aiming for such a bud. - Natsume uses her position as a teacher to sexually harass Tsubomi. - The serious bud thinks it's for swimming and accepts. - Tsubomi, who was straight, reacts to Natsume's naughty tongue tricks and learns that she is a lesbian. - Will she end up having soft lesbian sex that is different from that of men?