Onii-chan no Koto nanka Zenzen Suki Janain Dakara ne!! Episode 4

Junior High student Nao's brother complex is so strong, it's almost at the point of incest. She's determined to make her brother, High School student Shuusuke, see her as a woman. So determined, that she goes as far as going into his room to throw away all his non-incest related porn. But as she's looking for his porno stash, she finds a photo album... and she's not in any of his childhood pictures. What is going on?