When it is discovered that Mayu is the twin sister of Misa, the girl who has become Medusa, Mayu makes it her mission to seek out the one part of her sister that is still alive within Medusa, even though Haruto believes it is better to save Takako first.

When Debo Patissie causes Ian and Souji to get painful tooth cavities, Daigo, Nobuharu, and Amy must figure out how to call upon a new power.