Aishia

Aishia is Rio's contracted spirit as well as a high rank spirit, of which their existence are incredibly rare. and is willing to do anything for the sake of Haruto's happiness. Rio knows that she is an upper high class spirit after he met the Spirit of the giant tree, Dryad. Aishia was the one who taught Rio the Spirit Arts before he sets foot on Seirei no Tami after he fled from the Strahl region due to being framed for the Cliff incident. Prior to her awakening in her humanoid spirit form, Aishia spent the 3 preludes arc mostly by sleeping and residing within Rio. Rio would occasionally hear Aishia's voice briefly in a form of inner-monologue, where she tries to help and guide him out of his predicament. Aishia would eventually manifested herself and wakes up next to Rio on his bed after Rio successfully rescued Miharu, Aki and Masato from the slave traders.

Personality
Aishia is a caring and curious girl. She is devoted to Rio and will always accept him. She always wants to try living the same as humans do, eating good food, taking a bath, and wearing a cute dress. Though she's pretty blunt with her words, she has a weak expression. Almost expressionless most of the time, and she speaks in a monotone intonation.

According to Dryas, it's unnatural for Aishia to shown lack of expression as a spirit's personality should mature and when they reach high-class humanoid spirit. They should already have full personality, yet although already a humanoid spirit, Aishia is like a Medium class spirit mental wise, unless, being an expressionless character is indeed her personality. Also, when she manifested she had no memories aside from knowing all about Rio.