Responses
maybe this?
http://www.mangago.me/read-manga/rub_in_love/
No. That's not it. The uke looked younger than the seme. Also, the uke was found by the seme in the rain outside the seme home or workplace.
THAT'S IT! I didn't realize/remember it was just a one-shot.
Sorry, I forgot, but Thank you for you're help!
There is a manga that I read a long while and what to read again. It involves the uke living with the seme and the uke has amnesia. It eventually turns out the reason for the amnesia is because the seme hurt/killed someone close to the uke (or the uke himself).