She was assigned on a mission by Kagemusha to attack the Hidden Lantern Village during their Easter event. This ruined the Easter event for the villagers with her causing many damage to the village and people. She became the top figure to hunt during the Easter event instead of them hunting for eggs. She couldn't have ruined this village without the help of her loving pet, Zen, which is a black bunny. Together, they are unstoppable. Not to mention, no one knows what is behind that mask of hers with tags attached that looked similar to Kojima's. She is partner with Iketsu in the Kagemusha.
member of Kagemusha
She uses shadow techniques by using the shadows of objects around her and her own shadows. She is the shadow herself. She also uses swift techniques that makes her fast like her shadow movements. To make it worst for her targets, she also has her Zen pet with her to cause many blade slashes through the daytime of the day to cause a darkness for a limited time (since daytime is continious through the day) where Yosuzume and her pet can easily blend into the darkness. Yosuzume into her shadow self. Zen with its skin color. A total massacre within the darkness, especially when the night comes.