Responses
Idk if you're talking about this since it has multiple stories but the one you're describing is treasure quest. I think.
https://www.mangago.zone/read-manga/9733_s2/
That's exactly what I was looking for! You hero(づ￣ ³￣)づ Thankyou so much, have a great year and merry Christmas
Desperately looking for a manga where the guy finds a map among his deceased grandfather's things and then goes to a cave where he finds a beautiful man (seme) who is actually a half monster waiting for his grandfather, mistaken the uke for his grandfather and then **** the uke immediately