Popo is the first to encounter Kaiba upon awakening. After crossing paths with him again, he explains to Kaiba the nature of the current world, and that his life is in danger. Giving him the temporary name "Warp," Popo smuggles him onto the freight ship Neuron while creating a diversion for him to escape from Cloak, a man who is after Kaiba's special body.

Popo is the more public voice for the organization Issoudan, an anti-memory chip organization destined to destroy Warp for the wrongs he allegedly committed and rid the world of these supposedly evil technologies. Popo's real motivation is likely more nearly that he wishes to take this power for himself.

After the events before the first episode, Popo has Neiro's memories modified to make all her good memories of him and all her bad memories of Warp, ensuring her loyalty.