Miyata Ayaka, a diligent office worker, felt empty in her cold marriage with her husband. One night, Ayaka met a mysterious man named Sakurai by chance, who saved her and moved her heart. However, Sakurai was a dangerous figure living in the underworld. He was someone she should not be drawn to, yet she could not resist his feelings and desires. What awaited Ayaka when she stepped inside was an ending she could never have expected.