ONE N’ ONLY Members Profile 2026: Bio, Ages, Birthdays, Height & Interesting Facts

ONE N’ ONLY is a five-member Japanese dance and vocal group under Stardust Promotion and part of the EBiDAN collective. Known for their self-described JK-POP style, the group blends J-pop, hip-hop, Latin influences, and powerful choreography while building a strong international fanbase.

This profile includes verified member information, birthdays, heights, blood types, representative roles, and officially confirmed facts available as of 2026.

ONE N’ ONLY Overview

Group Profile

Group Name	ONE N’ ONLY (ワンエンオンリー)
Debut	November 24, 2018 (indie)
Major Debut	June 18, 2025 (Universal Music / Polydor Records)
Agency	Stardust Promotion
Label	Universal Music / Polydor Records
Members	5
Country	Japan
Genre	JK-POP, Dance, Hip-Hop
Fandom	SWAG
Official Color	Not publicly available

Note: ONE N’ ONLY currently promotes as a five-member group following lineup changes in 2025.

ONE N’ ONLY Members Profiles

TETTA (関 哲汰)

Stage Name	TETTA (テッタ)
Japanese Name	関 哲汰
Birthday	November 24, 1997
Nationality	Japanese
Birthplace	Kanagawa, Japan
Height	169 cm
Blood Type	B
MBTI	Not publicly available
Position	Vocalist

Verified Facts

1. TETTA is one of the original members of ONE N’ ONLY.
2. He serves as a main vocalist.
3. He was born in Kanagawa Prefecture.
4. His hobbies include gym workouts, saunas, driving, and collecting beauty products.
5. He enjoys karaoke as one of his favorite activities.
6. Drawing is one of his officially listed special skills.
7. He is also skilled at Taiko no Tatsujin.
8. He is part of the EBiDAN artist collective.
9. He continues promoting during the 2026 INFERNO arena tour.
10. His profile is officially published by Stardust Promotion.

REI (沢村 玲)

Stage Name	REI (レイ)
Japanese Name	沢村 玲
Birthday	January 2, 1997
Nationality	Japanese
Birthplace	Shizuoka, Japan
Height	177 cm
Blood Type	B
MBTI	Not publicly available
Position	Vocalist

Verified Facts

1. REI is a vocalist in ONE N’ ONLY.
2. He was born in Shizuoka Prefecture.
3. Cooking is both his hobby and special skill.
4. He enjoys watching baseball and combat sports.
5. Spicy food is one of his favorite specialties.
6. He is known for his fast-talking ability.
7. He is active as both a singer and actor.
8. He belongs to Stardust Promotion’s EBiDAN division.
9. He participates in the group’s international activities.
10. His official profile lists him at 177 cm tall.

EIKU (山下 永玖)

Stage Name	EIKU (エイク)
Japanese Name	山下 永玖
Birthday	December 19, 1999
Nationality	Japanese
Birthplace	Yamanashi, Japan
Height	170 cm
Blood Type	B
MBTI	Not publicly available
Position	Vocalist

Verified Facts

1. EIKU is one of the group’s vocalists.
2. He was born in Yamanashi Prefecture.
3. He enjoys fitness and fashion.
4. He plays guitar, drums, and bass.
5. Dancing is one of his strongest skills.
6. He is capable of acrobatic performances.
7. Gaming and billiards are among his hobbies.
8. He is part of the EBiDAN collective.
9. He performs on the 2026 INFERNO arena tour.
10. His official height is 170 cm.

HAYATO (高尾 颯斗)

Stage Name	HAYATO (ハヤト)
Japanese Name	高尾 颯斗
Birthday	September 17, 1999
Nationality	Japanese
Birthplace	Shizuoka, Japan
Height	176 cm
Blood Type	AB
MBTI	Not publicly available
Position	Rap & Dancer

Verified Facts

1. HAYATO is a rapper and dancer.
2. He started dancing at the age of seven.
3. Choreography is one of his special talents.
4. He enjoys improvisational dance.
5. Soccer is another officially listed skill.
6. His hobbies include shrine visits and mystery stories.
7. He loves Japanese pickled plums (umeboshi).
8. He represents ONE N’ ONLY’s performance line.
9. He celebrated his 27th birthday in September 2026.
10. He is signed under Stardust Promotion.

NAOYA (草川 直弥)

Stage Name	NAOYA (ナオヤ)
Japanese Name	草川 直弥
Birthday	April 6, 1998
Nationality	Japanese
Birthplace	Tokyo, Japan
Height	176 cm
Blood Type	A
MBTI	Not publicly available
Position	Rap & Dancer

Verified Facts

1. NAOYA is part of the rap and dance line.
2. He was born in Tokyo.
3. Fashion styling is one of his hobbies.
4. He is interested in skincare and beauty.
5. He enjoys movies and video games.
6. Soccer is one of his special skills.
7. He also creates dance formations.
8. He is active as both an idol and actor.
9. He remains a core member of the five-member lineup.
10. His official profile lists him at 176 cm.

Verified ONE N’ ONLY Facts

1. ONE N’ ONLY debuted as an indie group in November 2018.
2. The group belongs to Stardust Promotion’s EBiDAN project. スターダストプロモーション
3. Their musical identity is officially described as JK-POP. STARDUST RECORDS スターダストレコーズ SDR
4. The current lineup consists of five members.
5. They signed a worldwide deal with Universal Music / Polydor Records in 2025.
6. Their major debut single was BLAST.
7. The fandom name is SWAG.
8. Their TikTok account has over 5.6 million followers, making them one of Japan’s biggest male music acts on the platform.
9. Latin music heavily influences their recent sound.
10. The group completed a successful South American tour in 2023.
11. Every show on the 2026 INFERNO arena tour sold out.
12. HAYATO began dancing when he was seven years old.
13. REI is officially recognized for his cooking skills.
14. EIKU can play multiple musical instruments including guitar, drums, and bass.
15. TETTA’s special talents include drawing and rhythm gaming.

Official Social Media

Platform	Official Account
X (Twitter)	@onenonly_tokyo
Instagram	@onenonly_tokyo
TikTok	@onenonly_tokyo
YouTube	ONE N’ ONLY
Official Website	ONE N’ ONLY Official Site

More Info About Kpopbio

Medium	Follow
Pinterest	Follow
Tumblr	Follow
Pearltrees	Follow
Website	Follow