When Mizuki Natsukawa unexpectedly befriends Rei Utami, a boy who has been absent from school due to illness, their bond deepens in the nurse's office. Initially hesitant, Mizuki becomes captivated by Rei's charm and spends increasing amounts of time with him. However, a simple kiss complicates their friendship, leading Mizuki to question the true nature of their relationship. As tensions rise, Mizuki strives to uncover the reasons behind Rei's behavior and navigate the uncharted territory of their evolving connection.