Himi divorced her husband 10 years ago and raised Naoya single-handedly. Not wanting to evoke pity due to being a single mother, she worked tirelessly, and before she knew it, Naoya was old enough to graduate from university. With child-rearing coming to an end, Himi felt both relief and a sense of emptiness from losing her purpose. One day, Naoya invited her on a hot spring trip. Himi and Naoya set off on their graduation trip for two.
