Otonari no Tenshi-sama ni Itsunomanika Dame Ningen ni Sareteita Ken

Mahiru Shiina is admired at school as the "Angel": beautiful, capable, kind, and seemingly perfect. Amane Fujimiya lives in the apartment next door and has almost nothing to do with her until he finds Mahiru sitting alone in the rain and lends her his umbrella. When Amane falls ill afterward, she repays the favor by caring for him.

That should have ended their connection, but Mahiru cannot ignore the disastrous state of Amane's meals and apartment. Cooking for him becomes a routine, then shared dinners become comfortable evenings where neither has to perform the version of themselves everyone else expects. Behind closed doors, the perfect Angel and the careless loner slowly become simply Mahiru and Amane, and the distance between neighbors grows smaller without either noticing exactly when it changed.