Hinata ni Rin to Saku Himawarisou

The story follows Haruo, who one day loses his wife, Hinata, in a car accident. Heart-broken, he returns to the boarding house where his wife once lived, wanting to care for it in honor of her memory. This proves a difficult task as the current owner of the premises, his former sister-in-law, holds Haruo responsible for Hinata's death.

(Source: MangaDex, edited)