Prequel to Chou to Hana no Kankeisei.
Boys mother dies, he becomes the replacement for her. The uncle (not related) gets possessive, raises him, never lets him leave, the older he gets the more sexual it gets. In high school the unlce tattoos a womb on his stomach so that he never leaves and becomse his 'woman' but he gets abandoned anyway. The boy grows up and is the main character from story 1 in Chou to Hana no Kankeisei
Chou to Kumo no Su