Ai Shindou

Ai is a gentle youmu, she has a cheerful personality and seems to become easily excited. Ai is a spirit warrior. In spite of her youmu lineage, Ai lives alongside human society as a student of Nagatsuki City High School and assistant to Ayaka Shindou, who is also a youmu. She is also familiar with Akihito Kanbara and the Spirit World Warriors because of Ayaka's occupation as a youmu appraiser.
She has helped Mirai Kuriyama, Akihito, and Mitsuki and Hiroomi in catching youmu like the Fruit Type youmu on top of the school building by assisting in forming an idol band group in order to distract the youmu. However, since no one planned on who would finish off the youmu, they were sprayed with the youmu's defensive scent before they could attack, leading them to stink and need constant showering; it's called the youmu fruit incident.
Ai is also a good singer, as seen during the Fruit Youmu incident when she sang for their pop group, and often cosplays/models for her sister's photography work.