Kawatare, Kataware

After a fateful incident, the vampire Jaspers retreated into the timeless Forest of Mist, where nothing ever changes. Having lost his beloved dog and the loyal butler who cared for him, he wallows in solitude until his sister Abi, who once left the forest for the outside world, suddenly shows up at his door.
Before he knows it, Jaspers finds himself dragged back to Tokyo for the first time in 100 years, settling in Kiyosumi-Shirakawa and fumbling his way through modern life: from hunting for a life partner to figuring out how to be a proper uncle. For an immortal vampire, the hardest thing might just be keeping up with the living.

(Source: Kurage Bunch, translated)