When I returned to my parents' house for the first time in a while, I heard that my step-sister, who was born after my parents' remarriage, was apparently a shut-in, so I was worried and went to my sister.It seems that Koiro was teased for her big breasts, and that's why she's been shut up...and as she accidentally comforts Koiro and tries to do something that is typical of her older brother, her expression gradually changes...I'm a stepbrother and sister, so it's fine, and I'm a tempted man with her huge breasts, so I succumb to that charm.
