Saya is an oni dating a human guy. They are happy together, but there’s a secret she’s hiding from him: oni are naturally animalistic and select their mates by sexual prowess. She definitely likes him, but the relative who’s letting her live in his house... is an oni himself and thus much bigger than any human.
*All characters depicted in this work of fiction are adults, regardless of their visual representation or textual description, and are not based on any real person*