looking for this doujinshi , basically on this village they have the tradition of yobai or night crawl , where a man visits a womans room at night to have sex with the intention of marry , the femboy mc has a older sister and he has taken upon the task of protecting her , one night a guy comes in , and when he check the futon , he finds the mc with a knife , who tells him to get out , but the guy doesnt get scared , in fact he is happy and brings the mc to other room , where he explains him that he actually wanted him , they have sex and in the end theres a time skip where mc prepares himself for his wedding , and his older sister is like “i cant believe that xxx-kun is getting married before me…”