No.0
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.