[CHz]

LOVERSOUL music credits:

CAROL: Necktie, kutsuka, STEVE
Hanasaku Otome no Tame no Kiyuukyoku: Necktie, kutsuka, Soh Asagiri
Nusunde My Heart: Ryu Kawasaki, kutsuka, Soh Asagiri

So maybe Necktie = Ryu Kawasaki and STEVE = Soh Asagiri. The instruments played by STEVE and Soh Asagiri also line up (guitar, piano, violin).