Yong-hwa is a Prism Star Idol under the same agency as Puretty, and he's got the celebrity crush factor in spades—women tend to swarm whenever his name comes up. He first showed up in Episode 22 and eventually transitioned into acting, becoming a popular actor down the line.
He's got history with a couple of the main cast: he's childhood friends with both Chae-kyoung and Yun-su. One of his standout abilities is something he calls "Heart Shuffle"—he can read what people love most or figure out who they're into. He definitely uses this power for entertainment value, constantly teasing Reina about her obvious crush on Itsuki and finding her flustered reactions adorable.
His signature Prism Jumps are "Big Love Beam," "Smashing Love-Love Punch," and "Fighting Love-Love Stare," all introduced when he debuted.
Content compiled by AnimeList.moe from publicly available sources.