Since her husband's parents went on a trip, Hina has taken on the responsibility of caring for her father-in-law's elderly grandfather, Masajii. Though Masajii carries the traditional dignity and gravitas of an older man, caring for him proves far more difficult than expected, and Hina is met with unforeseen circumstances. Under the guise of caregiving, Masajii begins making sexual demands of Hina. With no choice but to comply, Hina gradually finds herself drawn in—not just physically, but deep into the recesses of her mind and emotions. Her relationship with Masajii evolves into something far beyond mere caregiving, forcing Hina to confront her own limits and raw feelings.