Kanpeki na Imouto wa Tabun Hentai - Ch. 17

[MangaDex]

 

[MontDilanus1343]

Is it just me, or are there subtle shadows on her shirt in the third panel?

 

[smormu]

I have a theory that if two siblings feel mutual attraction that it means they have better genetic compatibility than you would expect from any random pair of siblings. Humans can detect genetic compatibility in prospective mates through scent and pheromones, why wouldn’t this also apply to siblings who find each other attractive? Perhaps in cases where siblings are married for reasons other than mutual attraction, like political marriages in ancient Egypt, the negative effects of inbreeding were worse than they would be in sibling couples who married out of mutual attraction.

Simply put, if you and your sister find each other’s scent attractive then she is relatively highly genetically compatible with you!

 

[ItsThatBriGuy]

Is it just me, or are there subtle shadows on her shirt in the third panel?

She's probably supposed to be wearing just the jersey (having taken off her tee just moments before).