Yuzuriha, also known as Yuzuriha of Keishu, is a criminal kunoichi that has been put on death row.

After the shogun called for convicted criminals to acquire the Elixir of Life from the dangerous island known as Kotaku.

In exchange for a pardon for their past crimes, Yuzuriha accepted the invitation to be a part of the competition mission. Upon taking the mission, Yamada Asaemon Senta was chosen as her assigned monitor. Shortly after, Yuzuriha becomes a part of a united front formed from the remaining surviving criminals and executioners to defeat Lord Tensen, work together in capturing the elixir, and have everyone escape the island.

(Source: Jigokuraku Wiki)