Ani Love -Josou Bishounen Kakumei! | あにラブ ～女装美少年革命！～

The protagonist, Naoki lives alone with his older brother Yuuki. One day Naoki comes home and finds a strange girl there she is in fact Yuuki. It seems that Yuuki has started identifying as a woman. Naoki vows to turn his brother back into a man, but has strange feelings toward female Yuuki.