Samurai Lover, this one I very very like hahaha
The seme came from Meiji Era, which is an old period of Japan, and while he was being chased by the police after accusing him of a crime that he didn't did, he leapt on a water so he can escape, but ended up being sent to the present where he met the uke while he was soaking himself on a bathtub, the seme appeared right in front of him out of nowhere
Oh and another two that I'll add on my recommendations, Fukouchuu no Shiawase and Mother's Spirit, they're from the same author, or you can read sensei's other books as well, I think she/has another manga where the uke was delusional because his brother died so he mistook the seme to his dead brother and he let him live with him
anyone have any recommendations for mangas similar to the first story ? or just any where seme/uke live together due to unforeseen circumstances (⊙…⊙ )