I'm a librarian who loves anime, manga, and reading a wide variety of genres.
A few months ago I stumbled across a word for what turns out to be one of my favorite anime genres, although I didn't realize it had a name: iyashikei. It's a term for anime and manga specifically created to have a "healing" or soothing effect, and often crosses over with another favorite of mine, "slice of life." I came across this series after learning about that word - I'm watching it on Blu-ray, but it's also streaming for free on Crunchyroll.
(Content warning for the series:(show spoiler)
My Roommate is a Cat stars Subaru, a 23-year old introverted mystery writer who's dealing with both grief over his parents' death and social anxiety. Being around people and noise exhausts him, and all he wants to do is read books and be alone. However, he's also terrible at taking care of himself - he doesn't properly stock his kitchen, he forgets to eat when he's on a deadline, and his social anxiety is so great that even talking to store employees is hard for him.
While visiting his parents' grave, he encounters a stray cat, is struck with an idea for his next novel, and ends up taking the cat in, the first living being he has purposely allowed into his life since his parents' death. Each episode is generally structured to first show viewers Subaru's POV and then all or most of the same events from the cat's POV. There's often a mismatch between how they interpret events, but they gradually come to understand each other and form a little family, which also leads to Subaru allowing more people into his life.
I have about three episodes left, and I'll be sad when it's over. It's a sweet series with occasional sad moments - I recommend keeping tissues on hand for the flashback scenes. Haru, the cat, views Subaru like one of her siblings, someone who needs to be taken care of and watched over, but she also occasionally gets a little irked by him. And I can definitely relate to Subaru's introversion. Although he often finds that his interactions with others go better than he expected and open up his world in enjoyable ways, it still exhausts him all the same. The episode where his friend brought his younger siblings over was pretty much how things went when my sister brought all the kids to my apartment a few years back.