Masaki lost his father at a young age and has since lived with a woman named Ayaka. Over the years, Ayaka cared for Masaki as if he were her own child. Touched by her warm affection, Masaki gradually began to love Ayaka not just as a mother figure, but in a deeper, more passionate way. After graduating from university, Masaki landed a job in the Kansai region, forcing him to live apart from Ayaka. Internally, he felt lonely and heartbroken over the separation. Then, unexpectedly, Ayaka invited him on a hot spring trip. Seizing this opportunity, Masaki resolved to confess his long-suppressed feelings to her. In expressing his true emotions, their relationship takes a bold, new turn.