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.
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
It leans heavily into the "imouto" (little sister) tropes popular in the early 2010s, similar to series like Oreimo . The series was famously picked up for international