Mayu's past and why she ran away from home are revealed. Mayu's mother remarried, and her new stepfather repeatedly molested her. When her mother refused to offer her any help, she ran away from home, where she encountered a stray dog, whom she named "Wanta". As Kohta and Yuka enter university and take Nyu with them, Professor Kakuzawa, the son of Kurama's boss (and, by coincidence, the university lecturer) discovers Nyu and she is taken from Kohta and Yuka. Kakuzawa is revealed to be partly diclonius, and intends to breed with Lucy. However she simply kills him, claiming that he is worthless in the evolution towards a diclonius-populated world. Kohta finds out it is also Mayu's 14th birthday, and invites her to stay permanently with them, where she finally feels that she has a family who cares for her.