No premiere date announced yet. Check out the Crunchyroll article for additional information. Synopsis of the source novels from AniList:

Amane lives alone in an apartment, and the most beautiful girl in school, Mahiru, lives just next door. They’ve almost never spoken—until the day he sees her in distress on a rainy day and lends her his umbrella. To return the favor, she offers him help around the house, and a relationship slowly begins to blossom as the distance between them closes…