In the pleasure district of Yoshi-chō during the Edo period, men sell their bodies at establishments called kagema chaya, teahouses where male prostitutes, known as kagema, entertain clients. One such house, Shisenrou, is run by a family who have operated it for generations. Ichika is the daughter and heiress of Shisenrou, raised to one day inherit the role of the establishment's mistress. When she is six years old, she rescues a beautiful boy named Noa from drowning in a river. Unbeknownst to her, Noa was being transported to be sold as a kagema for Shisenrou itself. He is brought into the household, and the two are raised together almost as siblings, with Noa attending school alongside Ichika through her father's arrangement.

As they grow into young adults, their relationship becomes strained by the realities of their positions. Ichika eventually discovers the true nature of the work that takes place on the second floor of Shisenrou, a part of the building she had been kept away from as a child. She is devastated to realize that Noa too is destined to become a kagema, and she blames herself for having saved him from the river, believing that her intervention set him on this path. Noa becomes one of the most popular figures at Shisenrou, while Ichika inherits the role of mistress after her father's death. Their childhood bond deepens into something more complicated, but a relationship between a mistress and a kagema is forbidden, and the power imbalance and social codes of their world make any genuine connection dangerous for both of them.

The story follows the two as they navigate a world thick with desire, rivalry, and violence. The narrative arcs include the opening of an event called kagema kabuki, a performance that puts Noa in the spotlight and draws the predatory attention of a character named Chōko. Noa is eventually taken by a rival establishment called Kinmonjiya, throwing Ichika into despair. Around the same time, she learns that the person who killed her father may be among those within Shisenrou, adding a thread of mystery and revenge to the central romance. The characters must reckon with their feelings and their fates within a world where the only way forward may be to escape the very systems that defined their lives. The story concludes as the two choose their future, with the cycle of suffering finally breaking and allowing something new to bloom.