Ueno Seiji

CLOUDTENPEDIA - Ueno Seiji (上野 誠治, Ueno Seiji, born November 1, 2003) is a Japanese idol, dancer, and member of the boy band Cloud ten, a theater-based male idol group produced by Yasushi Akimoto. He is known for his neutral, androgynous appearance, his braided hairstyles, and his background in design and color coordination. He joined Cloud ten as part of its inaugural thirty-member lineup in April 2026.

Early Life and Background

Ueno Seiji was born on November 1, 2003, in Miyagi Prefecture, Japan. Standing at 171 cm, he is one of the taller members of Cloud ten. Before entering the entertainment industry, Ueno had a strong interest in design and visual arts. He possesses a color coordination certification (色彩検定), demonstrating his formal training in color theory and aesthetics. His hobbies include cosplay, collecting merchandise of his favorite characters—notably Momonga from Chiikawa—and creating custom goods for his pet dog. He is particularly skilled at producing LINE stickers and picture books, which he has made for his beloved dog.

Ueno's admiration for the idol industry began in his youth. He has cited former AKB48 member Mayu Watanabe as his primary inspiration, admiring her professionalism, work ethic, singing ability, and scandal-free career. This admiration shaped his aspiration to become what he describes as a "royal road idol" (王道アイドル)—an idol who is loved and trusted by many. Approximately three years before his debut, Ueno wrote a letter to Yasushi Akimoto requesting that he produce a male idol group, a gesture that foreshadowed his eventual entry into the industry.

Cloud ten

Formation and Concept

Cloud ten (クラウドテン) is a Japanese male theater idol group formed under the joint venture "From ZERO LLC," established in 2025 by Mitsui Fudosan, Tokyo Dome Corporation, and Y&N Brothers, with Yasushi Akimoto serving as general producer. The project, originally titled "Theater Boys Group," conducted a nationwide audition starting in summer 2025, seeking talent aged 12 to 26 as of August 2025. The final thirty members were announced on April 23, 2026, at a press conference in Tokyo.

The group's name derives from the English idiom "Cloud nine," which signifies a state of supreme happiness. By naming the group "Cloud ten," Akimoto and the production team intended to convey a mission of surpassing even that highest level of joy, delivering an unprecedented degree of happiness to audiences. The group's creative philosophy centers on Akimoto's belief that "the greatest treasure in life is to witness something"—specifically, to witness the moment when individuals transform from "zero to one". The dedicated theater's design concept is modeled after New York's Off-Broadway, emphasizing intimacy between performers and audience.

Debut and Theater Activities

Cloud ten made its formal debut with a dedicated theater, "Cloud ten THEATER," which opened on August 2, 2026, within DiverCity Tokyo Plaza in Odaiba, Tokyo. The theater's first performance featured all sixteen songs from the group's debut stage, including the opening number "We're Cloud ten," as well as "Kimi wa Kimi da" (You Are You), "Taiyō no Katamukikata" (The Way the Sun Tilts), and "Gomen Ai Koso Subete" (Sorry, Love Is Everything). The debut performance was noted for its intense energy, with some reports describing sweat flying as far as the audience seats, underscoring the group's commitment to high-energy live performance. The group's stated goal is for all thirty members to eventually perform at Tokyo Dome.

Role Within Cloud ten

Member Profile

Within Cloud ten's thirty-member structure, Ueno Seiji is recognized as a member of the first generation and performs in various configurations, including full-group numbers and smaller unit performances. He has been featured in several of the group's signature songs, including "Colors of Us," "Kimi wa Kimi da," and "Eyes on me," often performing alongside members such as Uji Toma, Owada Ayumu, and Komai Riku.

Ueno's self-identified strengths lie in his neutral, androgynous appearance and his distinctive styling. At the group's debut events, he adopted braided hairstyles and pink makeup—unconventional choices for a male idol—which he believes help him stand out and capture audience attention. Beyond his visual presentation, Ueno emphasizes the importance of precise, elegant dance movements, particularly paying attention to his fingertips and overall line. He also identifies his ability to observe his surroundings and understand the role expected of him as a key asset, approaching his work with a mindset of fully committing to whatever is asked of him.

Public Statements and Recognition

Ueno has been featured in Cloud ten's major promotional initiatives, including a large-scale serial interview series published by Iza in July 2026, where he was introduced as possessing a "sincere personality" (誠実な人柄) that reflects his name. In this interview, he described his audition experience as the realization of a long-held dream, stating that even after being selected, he sometimes questioned whether it was real. He expressed particular joy at seeing fans bring name boards to events, which confirmed for him that he had truly become an idol.

In September 2026, Ueno participated in Cloud ten's first major external performance as an opening act at the 43rd Mynavi Tokyo Girls Collection 2026 Autumn/Winter, held at Yokohama Arena. Performing alongside ten other members in red-toned costumes, he and his groupmates delivered the original song "Gomen Ai Koso Subete" to a large audience. Ueno commented that the venue held personal significance for him, as it was the first place he had ever attended a live concert, making his performance there as an opening act a deeply meaningful experience.

Artistic Identity and Goals

Performance Style

Ueno's performance identity is closely tied to his background in design and color theory. He approaches stage presentation with a visual artist's sensibility, considering how his appearance, movements, and styling can create a compelling aesthetic impression. His decision to incorporate traditionally feminine elements—braided hair, pink makeup, and delicate, fingertip-conscious dance gestures—into his male idol persona reflects a deliberate artistic choice to differentiate himself within the group. This approach aligns with Cloud ten's broader mission of showcasing diverse individual talents within a theater format, where each member's unique qualities can be highlighted.

Future Aspirations

Ueno has articulated clear goals for both his personal career and Cloud ten's trajectory. Individually, his ultimate ambition is to become a "god idol" (神アイドル), a term connoting an idol of the highest caliber who is widely beloved and respected. He draws this aspiration directly from his admiration for Mayu Watanabe, aiming to emulate her professional dedication and enduring popularity. On a group level, Ueno has stated that Cloud ten's collective goals include performing at the Tokyo Dome, appearing on NHK's Kōhaku Uta Gassen, and winning the Japan Record Award. He has also expressed a desire to communicate to a wider audience the warmth and humor of his fellow Cloud ten members, whom he describes as kind and entertaining individuals.

Personal Interests

Outside of his idol activities, Ueno maintains a variety of creative and personal interests. His design skills extend beyond professional application into personal projects, including the creation of custom merchandise for his pet dog and the production of LINE stickers and picture books. He enjoys cosplay and collecting goods featuring the character Momonga from the popular series Chiikawa. His affection for his dog is a recurring theme in interviews, where he has mentioned both creating goods for the animal and taking it for walks as part of his daily routine. These personal pursuits reflect a personality that values creativity, comfort, and affection—qualities that inform his public persona as a sincere and dedicated performer.