Itsuki Harune
Itsuki is Aira’s 14 year old little brother who usually teases her and is the object of Reina’s affection. He is younger than Aira but is more mature and not as clumsy. Itsuki helped her keep the secret about being in the Prism Shows from her dad together with their two younger twin sisters. It looks like he has an interest in doing the family business. Itsuki is studying to be a sports doctor at a young age.
Mia pointed out he has no excitement and got him involved with a Prism Surprise Show. Itsuki is interested in Prism Shows, despite not watching many of them. He made his Prism Show debut in Episode 15. Itsuki seems to be interested in Reina. It wasn’t until Episode 22 that Prizmmy found out that he and Aira are siblings. He displayed feelings for Reina in Episode 51 when he asked her if she wanted to hang out. In the future, he became a sports doctor after graduating from college.