Looking for a manga that may not exist

[Enderdragon6095]

It’s about a guy and two girls trying to go out with him one has black long hair another blonde and short I think so here’s where it gets weird so half way through the manga I think some type of monster traps or devoured and transforms into the black haired girl and she eventually wins with the blonde eventually finding a boyfriend a year or so later. I think the real black haired girl is watching the person she loves go out with her double and that’s all I can remember. I know it probably doesn’t exist but if you find do tell.

 

[Ferreas]

Definitely not the thing you are looking for
But for a manga with somewhat resembling vibe check out Summertime Rendering