His simple minded younger sister Kobato is an incest-loving slut.
But being so easy, she also starts having sex with behind his back with his classmate.
The exploit is the thrill, and she loves the feeling of stacking taboos...!
Not only does she f*ck her own brother, she f*cks others to shame him!

Brother-sister sex and netorare/cuckoldry,
starring Kobato from Boku wa T*modachi ga S*kunai.

[From DLsite English]