My Older Sister, Falling Into Depravity, And I, Helpless,~ My Admired Beloved Reveals Her Lewdness And Shame ~ ^Final

I was being targeted and bullied by delinquents.
But I continue to go to school every day because I can walk to and from school with my beloved Sis-Yumi.
I've admired her since I was little, and before I knew it, I had developed feelings for her.
She must not realize that I'm being bullied.
But finally, Sis-Yumi found out—
"Don't worry... Hiro-kun, I'll protect you."
Sis-Yumi, who tried to protect me and was attacked by the delinquents, ends up becoming one of them.
Gradually, she becomes tainted by the delinquents, both physically and mentally, falling into depravity.​

Game is avaialble for Windows