Ane Chijo☆Max Heart

Gifted with both beauty and intelligence, honor student, Kisaragi Sarasa, holds back her swelling desires and nosebleeds as the day has finally come. Her younger brother, Kira, was admitted into the same school as her, and to celebrate, she invited him to her room, preparing to give him her first time. Not realizing this, he goes in not suspecting a thing. In her see-through negligee, she jumps on him and stares him down with her eyes full of lust and breasts showing.

(Source: hanime.tv)