One day, Mami was riding her bicycle while playing with her smartphone when she collided with Tomoeiya, who had rushed out of the gate after oversleeping. Seeing Mami apologize, Tomoeiya schemed to take advantage and pretended to call her company, making Mami mistakenly believe she had been fired for being late. Exploiting the fact that Mami had been looking at her phone while cycling, Tomoeiya pressured and then assaulted her.