Mitsuki becomes possessed by the spirit of a young, amnesiac ghost named Hiyori. To pass on to the afterlife, Hiyori must "ascend" by experiencing love and fulfillment through Mitsuki. The catch? Hiyori forces Mitsuki to wear a supernatural chastity belt that can only be unlocked by performing increasingly bold and romantic acts with her stepbrother. Why It Stands Out

The series was famously picked up for international audiences by Crunchyroll , where it is available for streaming in various regions including North America and Europe.

The "TST" (Total Strategic Trapping) belt serves as the central plot device, driving the comedy and the tension by forcing Mitsuki into awkward situations.

It leans heavily into the "imouto" (little sister) tropes popular in the early 2010s, similar to series like Oreimo .