Kota grew up in a single-parent household, but even after he became a university student, he was still dependent on Yui. Yui had spoiled Kota, not wanting to cause him any hardship because he was from a single-parent household, so she realized that it was her fault that Kota had become a mama's boy. Kota is now in his third year of university, but if he carries on like this, he will not be able to enter society. Yui invites Kota on a trip to a hot spring, hoping that it will be a chance for him to become independent.