From Lezhin:

San once found comfort in Heemin’s kindness. Years later, he confesses the love he has kept hidden, not to win Heemin over but to finally walk away with closure. To his surprise, Heemin accepts his feelings without hesitation. Struggling to trust something that feels too easy, San finds himself torn between doubt and longing. He yearns for a kind of love he has never learned how to receive. A tender and tangled love begins between a black-haired beast still learning how to be human, and the man who never turned him away.

Original Webtoon

Official Translations:
English: Lezhin
Japanese: Beltoon, Lezhin
Others: T.Chinese, Thai

Note: The official T.Chinese translation is uncensored.