Sakral Ritter Mizuki

Mizuki is a cheerful busty girl. One day her favorite mascot Angel Pudding appears and tells about strange incidents happening in the neighboring boys school - a lot of boys get arrested at the shopping district after acting as if being possessed by demons. Mizuki and Saya accept this mission and become warriors of justice. But they get kidnapped by these boys commanded by a mysterious man. Girls get tied with their ribbon weapons and are dragged to the bottom of shame.

[From vndbreview]