Mahiru Shiina, the school's revered angel graced with breathtaking beauty, shares an apartment building with Amane Fujimiya—an unremarkable student living independently. Their separate worlds collide during a rainy encounter that shifts everything. When she offers him shelter with an umbrella, a witty, bittersweet bond emerges. «I'm returning what I borrowed. By the way, clean up your room. It's filthy.» «None of your business.» Their sharp-tongued dynamic evolves into something deeper: caring for one another through illness, preparing heartfelt meals, tidying rooms together, and discovering that the smallest daily gestures become the greatest expressions of affection and devotion.