Well I can remember that this manga was a part of various oneshots and that it was about a guy who I think was in a Cafe or something and then some other guy mistook him for his dead lover. Then I don't know how they started to have a relationship but the first guy was insecure because he thought that he was just a replacement. One day when he came out of the bathroom he found the other guy sleeping and when he was going to kiss him he called him by the other guy's (dead lover) name.
Then he ran away and if I remember correctly I think it was raining. Later the other guy found him and blablabla they ended up together again XD

Any ideas?

"I exist, that is all, and I find it nauseating" -Sartre

is it the fourth story in gouman na junai?

Quote from pinkprincess

is it the fourth story in gouman na junai?

OMG!! I think I love you! XD
I've been looking for this for so long...THANK YOU! 😀

"I exist, that is all, and I find it nauseating" -Sartre