Jōji Takadanobaba, a male student at Schwarz Rose Academy and Prism Star, hails from Okayama Prefecture and celebrates his birthday on September 15. His surname originates from Takadanobaba Station on Tokyo's Yamanote Line, meaning "high horse grounds," while his given name "Jōji" also translates as "George."

Standing 175 cm tall, he possesses short, bright blue hair and yellow eyes. His Prism Show performances feature a jester-style outfit marked by a distinctive pink heart on his left cheek, and his designated image color is "Pine Yellow."

Jōji exhibits an upbeat, attention-seeking personality with self-centered tendencies. He openly delights in winning, even resorting to cheating, and feels no shame about relying on lip-syncing due to his inability to sing. A "ghostsinger" named Ace provides his vocal tracks. Jōji consistently pursues the affections of Schwarz Rose's instructor, Jin Norizuki.

Initially leading Schwarz Rose unit "The Shuffle," Jōji's childhood friend Miyo revealed his original name was Noriyuki Motokawa. During the Prism 1 Grand Prix, he performed "JOKER KISS." Technical sabotage by rival unit YMT29 disabled Ace's microphone mid-performance, forcing a restart. With Ace's assistance, Jōji executed four Prism Jumps, earning 9,270 karats. Following this event, he transitioned to a solo career while Ace assumed leadership of The Shuffle.

His song repertoire includes "LOVE♥MIX" (a cover from the Pretty Rhythm series), "Koi no Royal Straight Flush," "JOKER JOKER," "JOKER KISS," and "JOY." His speech is characterized by the sentence-ending phrase "~joy!" He favors peaches as his favorite food and is right-handed.