After the disappearance of Ai Enma, the Hell Girl, her former companions attempt to lead normal lives until Ai unexpectedly returns with a new companion, Yuzuki Mikage. Yuzuki, a regular schoolgirl, becomes intimately connected with the Hell Girl after a surreal encounter where Ai possesses her through a kiss during a trance. When Yuzuki's friend uses the Hell Correspondence website to send their teacher to hell, Ai seizes the opportunity through Yuzuki's body. Struggling with her newfound role, Yuzuki questions why she was selected to continue Ai's grim task. Despite her reservations, the Hell Girl and her allies reignite the operation of Hell Correspondence, pulling Yuzuki into a dark journey towards the depths of hell.