On the run for crimes she did not commit, disgraced noblewoman Charlotte Evans collapses deep in the forest. A sorcerer named Allen Crawford—also known as the "Demon Lord"—finds and defends Charlotte from her pursuers. Since she has no place left to go, Allen takes pity on Charlotte and offers to hire her as a live-in maid. Allen quickly realizes that Charlotte has faced ridicule and hatred all her life from her so-called noble family, and she has never known what true freedom feels like. He decides to teach her about all the naughty things the world has to offer and enables her to surrender to her whims and impulses. Charlotte's sweet innocence proves an obstacle to his plans, but Allen is determined to show her the kind of life her family has denied her. Although he despises being social, Allen begins to open himself up to Charlotte. The longer they live together, the more they discover their similarities. Though most people have abandoned them, the duo promises to stay together, oblivious to their budding feelings for each other.

High schoolers Mio Miyamasu and Arata Kishimo are childhood friends. Mio harbors feelings for Arata, but she lacks the courage to express them. Even when her friend Madoka asks if she is in love with Arata, Mio reluctantly declines and encourages her friend to pursue her own feelings for him instead. Later, while Mio and Arata visit a fortune-teller, the boy notices a strange phenomenon and tries to drag Mio out of the shop—much to her annoyance. As Mio begins to question her relationship with Arata, an argument erupts between them. That night, feeling guilty for what had occurred, Mio ventures into the rain to apologize to Arata and make her feelings clear. However, an accident along the way turns Mio's world upside down.