One guy is a high school student who fell in love with his sister. Knowing that this was incest but his emotions were always dominated by her beauty. He secretly turned her changes and had a lot of clips in the phone. One day the friends discovered those clips in his phone, they robbed it and would use it to threaten his sister Hikari Ninomiya and force her to have sex. Indeed, the next day they came to Hikari's house and rape her, the younger brother only looked silent at her fuck in helplessness.