I don't recall much about it, but I remembered reading a Japanese manga wherein the main character is a high school guy who somehow ends up getting a wolf's tail. Furthermore, his male friend also ends up with an animal characteristic, namely bird wings, and became a villain for a few chapters.
And that's all that I can remember... oh, and some sort of chain that, if I'm not mistaken, makes him stronger or something. I've read it through an application called Manga Rock, but it can no longer be accessed now.
Any clues as to which manga closely resembles this?