disegni e storia: Ran Hiryu

The volume is in Japanese, so I can only guess the story.
Bondage story set in a Catholic school for girls.
A couple of girls have an intimate encounter in church and are surprised by another student (with glasses, therefore a class monitor or otherwise nerd).
The girls immobilize her and involve her in their erotic games.
When they find out that the young girl has lost her virginity to her brother, they decide to fuck her with a fake dildo as well.
The relationship progresses and they end up visiting her at home.
They manage to hypnotize his brother and disguise him as a woman, to then make them mate again.
Some time later we find the two girls involved in intimate relationships with other students, always with a strong bondage component.
Very simple designs, reminiscent of the anime "Pollon".
The situations are always humorous, so the bondage aspect is diluted.