Every hectic morning, with both parents rushing off to work, Oki drops his son off at daycare. He and Waka, his son’s teacher, have never been more than a parent and caregiver exchanging casual small talk. After Waka disappears from the daycare for several days, Oki finally sees her again and realizes her usual cheer is gone. When he asks if she is all right, she opens up about the heartbreaking events of the past few days. Seeing the vulnerable side hidden beneath her bright, dependable demeanor, Oki cannot bring himself to leave her alone. Even though they both understand the boundaries between them, they ultimately cross the line into a secret affair.