Boku No Futatsu No Tsubasa is a manga by Yui Toshiki. It opens with schoolgirl Hiromi being excited that her cousin Mako is coming to stay with her and her mother. Hiromi remembers playing with Mako when they were little, and is hoping "he" has grown into a handsome young man. However, when Makoto shows up as a very buxom young woman, it starts of a chain of misunderstandings, secrets and cover-ups. This is an Ecchi manga and features adult situations, explicit sex scenes, and nudity. Some of this is played up as fanservice, but there is a lot of sex tied into the plot as well.