(Im sorry for this is QUITEE long)
Runie: GYM BROS AND BROS FO LIFE!! Runie would find Kojo cool like a big brother!! He admires his fashion and how he can make songs. Runie would give him snacks sometimes when he visits Kojo or give him little knitted keychains (honestly he’d give them to anyone hes very close with and theyd symbolise what they are to him). Runie would give Kojo knitted pokemon keychains of his favs, symbols of his favorite artists/bands or something that he’d like and mentioned off handedly.
Damian: Sees Kojo as a little brother and has fun teasing him (even though they’re both certified yearners LOL) He enjoys making songs with him and Maeve and loves singing together with them as well. I’d think that Kojo has pictures of every emotion Damian has ever made due to how dang expressive that man is with his emotions. Overall a more familial bond.
Sonia: has a small admiration for him! He’s not CLOSE close with him but I think she’d get along with him well. Her tiny crush/admiration doesnt get that far though, she likes him as a friend and a colleague than as a lover. Sonia would hang out with him sometimes in coffee shops or help him, Damian and Maeve to fix their music equipments as she has a hobby of fixing things. :)
Shen Qinru: Would NOT like him. Shes a very haughty and very confident girl but doesnt like him because of his personality. She’d openly show her dislike for him which (sorry if I mischaracterize your character pls correct me if i did!!) would make Kojo annoyed and always give her the stank eye. I feel like their dynamic would embody the song What is this Feeling from the Wicked Musical LMAO! (Of course they’d both mellow down as they grow up but theyre still very snarky with e/o)