Number 96, when not in its card form, appears as a black version of Astral. Like its other counterparts, Number 96 is a malicious entity who desires the power of the other Numbers so that it may become the most powerful of them all. However, it is cunning enough to allow itself to be absorbed by Astral so that it may possess him from the inside and steal his "Numbers." It also enjoys sadistically manipulating its hosts and brutally defeating its enemies. Number 96 considers its card version to be its "other self." It also considers itself to be the "darkness" to Astral's "light." (Source: Yu-Gi-Oh Wikia)
An Artificial Intelligence Robot that Gennai created, it is capable of human interaction where it has form a certain attachment to Aoi. It is often in charge of monitoring everything that goes on in the dome. (Source: anilinkz)
A mysterious figure who watches Souta and his interactions with the various girls. Though she seems antagonistic, she has also helped them out, such as eliminating a renegade android attacking Souta, Nanami, and Hakua. She is later revealed to be Kagura Bladefield, the founder of the Bladefield Principality, who also bears a striking resemblance to Nanami, one of the current princesses of the kingdom.