Responses
*spoiler*
Actually there is a sequel where we can see his past and the origin of this tatoo, it's a bit fucked up but well...
It's not because he was hermaphrodite or anything
You can read the prequel here http://www.mangago.zone/read-manga/chou_to_kumo_no_su/
It shows how he got that tattoo
Call me dumb but was Chouno born with both genitals or like just a womb or like am I completely off