A girl who shares an unknown connection with Kaiba. Little is known about her, although she is currently under the care of Popo and a memory merchant. In episode 2, a broadcast reports about a "memory tank" exploding, releasing thousands of memories into space in the form of orange egg capsules. It is believed that Neiro is responsible for this incident.
Neiro grew up alongside Popo, and has been involved with Issoudan for a very long time. She is largely under Popo's control, and he has her convinced that should she get into trouble, she has no other place to return to.
In the events of episode 10, just prior to the first episode, Neiro meets Kaiba and falls in love with him, and when he leaves she is sent to his palace to kill him. When the two of them abscond from the palace and fall through the clouds, Kaiba preserves her memories, but she falls back into Popo's hands.