Nao's often busy at work and as a result, she's sleep-deprived. Though she's always tired during the day, she just can't close her eyes at night. But tonight, as she's reading manga on her phone again... a mysterious hottie appears next to her bed! He claims to be a sandman, and despite his intense lecture on her waking habits, Nao's not convinced he's real. Frustrated, he says he'll do his job if she sleeps with him. But... what kind of "sleep" does he mean!? Nao is now the target of a devilish sandman, who spoils her physically and emotionally. Their passionate life together has just begun!