Recently, My Sister Is Unusual -

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

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 Recently, My Sister is Unusual

The story follows Mitsuki Kanzaki, a high school girl whose life is turned upside down when her mother remarries. Suddenly, she has a new stepbrother, Yuya, whom she finds difficult to bond with. However, family tension is the least of her worries. The "TST" (Total Strategic Trapping) belt serves as