蝕獣～妹のおしり～ 美羽編

One morning, when Takeru wakes up, he finds himself transformed into a tentacle. Also, he rapes his younger sister, Miu, who comes into his room to wake him up. But soon after he ejaculates, he returns to his normal body. It seems his body is changed due to Miu. She secretly made a recall in her room last night. As a result, a monster appeared and possessed him. She tries to get rid of it, but she can't make it. She finally discovers that he will be able to control the tentacle through training. Like this, she decides to give him a hand...

[From ErogeShop]