My Roommate is a Cat(2015)

Doukyonin wa Hiza, Tokidoki, Atama no Ue.

Subaru Mikazuki is a writer who lost both parents in an accident. He rarely goes outside and finds interacting with people an annoyance because they intrude on his imagination. However, his encounter with a stray cat gives him inspiration for a new novel. As Subaru and Haru grow closer, Subaru slowly finds his world expanding, as Haru helps him remember what having a family is like.

(Source: Lezhin)