Kenji Sakamura is a timid, socially awkward 21-year-old stuck in a mundane life—until his mother arranges a date with Aoi Takahara, a confident and seemingly kind girl. Though hesitant, he agrees, only to later discover that Aoi was merely playing along due to pressure from their parents.

But Kenji harbors a darker secret. By day, he’s a quiet nobody. By night, he becomes Rei—a smooth, charismatic figure who prowls the city’s underbelly, hiding a violent, bloodstained side beneath his harmless facade.

As Aoi spends more time with Kenji, she starts noticing cracks in his awkward persona. Meanwhile, Kenji grows suspicious of Aoi’s intentions—why did she agree so easily? What is she hiding?

When a brutal encounter forces Aoi closer to the truth, she must decide: will she expose the monster behind the smile, or become part of his deadly world?