Gakuto Haruka is the youngest member of the idol group JAXX/JAXX, aged 15-16. His full name, 春賀 楽翔, reflects his persona: the surname Haruka (春賀) signifies "spring" and "congratulations/joy", while his given name Gakuto (楽翔) combines "music/comfort/ease" with "soar/fly". He hails from Ehime Prefecture and celebrates his birthday on August 6th.

Physically, Gakuto stands 174 cm tall and weighs 55 kg, with blood type AB. He has vibrant orange hair styled to ear length and distinctive green eyes.

Gakuto radiates infectious optimism and charisma, serving as JAXX/JAXX's primary mood-maker. He frequently engages in playful teasing, especially with fellow member Kanata Morinomiya. His interests include a fervent passion for music, animals, baseball, and eating.

Before joining JAXX/JAXX, Gakuto independently composed and uploaded original songs to social media under the pseudonym "Haruka". This established his dual role within the group as both a vocalist and composer. Across official media, including the anime, he contributes vocals to group performances like "A.P.P.L.E." and collaborative tracks such as "Yume no Tobira" with members from other agency units. His role centers on providing vocal and compositional skills while consistently uplifting group dynamics with his cheerful persona.