A Man and His Cat, Vol. 1

An older man adopts an unloved, unwanted kitten to fill an empty house, and together the two start building a (super cute) life together. Fukumaru discovers what it's like to be loved, wanted, and spoiled, while Kana (the man) remembers what it's like to have someone to come home to again.

I'm not entirely sure I can convey how incredibly wholesome this manga is. There's evidently some loss or tragedy in Kana's past that we haven't explored yet, but Fukumaru learning what it means to be someone's pet is incredibly sweet and cute. It took me forever to find a copy of volume 1, and already I can't wait to get volume 2!