Responses
I don't think it came from a possesive place. It might just be my interpretation, but i think it was a more "take back your power" kind of place. There a very few things more personal, than your name, by letting only the monster know and use it, the boy loses himself. By giving his name to our seme, he takes back his name. In essence his power.
I don't like that the reason on the last page, of him giving that neko a name is still related to a piece of sh*t. I wish he just wanted to name him because, I don't know, he likes him or feels for him at least (cuz he's kind)? And I want that name to be cute and meaningful and to be the one mentioned in that last page instead of a jealous-of-a-piece-of-sh*t possessive statement.