D-ONE Member Profiles 2026: Complete Guide to the Korean Boy Group You Need to Know

D-ONE (디원) is one of the most exciting 5th generation K-pop boy groups you should have on your radar right now. Under Mainbase Entertainment, this South Korean boy group has built a loyal fanbase — known as Diary — with their unique blend of K-pop dance pop, emotional vocals, and raw performance energy that sets them apart from the crowd.

If you love discovering nugu K-pop groups (that’s insider speak for underrated acts) before they blow up, D-ONE is exactly the kind of group you want to follow closely in 2026.

Here’s a quick look at everything you need to know about the group:

• Group Name: D-ONE (디원)
• Name Meaning: “D-1” refers to the day before a special occasion — a moment full of anticipation and excitement. D-ONE aims to be that source of excitement for their fans every single day.
• Label: Mainbase Entertainment
• Korean Debut Date: November 26, 2022 (with debut single “Torch”)
• Japanese Debut Date: August 27, 2023 (with single “One Dance”)
• Genre: Dance-Pop, K-pop
• Current Members (2026): Jaehoon, Hyunwoong, Ihwa, Sejin, Han, Jooyoung (6 members)
• Official Greeting: “Hello. We are D-ONE!”
• Fandom Name: Diary
• Status: Active
• Official Social Media:
  • Instagram: @done_officialjp / @done_official_mb
  • X (Twitter): @DONE_OFFICIALJP
  • TikTok: @d_one.official
  • YouTube: D-ONE OFFICIAL

Quick Note for New Fans: D-ONE started as a 5-member group but went through some lineup changes. Original member Doyul departed in August 2023, Sejin joined in November 2023, and most recently, Jooyoung officially became a member in early 2025 after completing his training. The current 6-member lineup is the most complete the group has ever been!

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D-ONE Member Profiles 2026

Member Overview Table

Here’s a snapshot of all six current D-ONE members so you can get to know them at a glance:

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Jaehoon — The Leader Who Sets the Stage on Fire 🔥

Jaehoon is the heart and soul of D-ONE. As the group’s leader, main vocalist, and main dancer, he carries a triple role that very few idols can pull off — and he makes it look effortless. Born on January 2, 1997, this Capricorn brings discipline and warmth to everything the group does.

He was the third member revealed for D-ONE, announced on October 7, 2022.

Jaehoon holds the triple crown of leader + main vocalist + main dancer — an extremely rare combo in K-pop.

As the oldest member of D-ONE, he naturally stepped into the role of leading the group with a calm, steady presence.

He is a Capricorn, which fans say matches his responsible and driven personality perfectly.

Jaehoon tends to be the member who holds everyone together during stressful schedules and performances.

His stage presence is often described by fans as magnetic — once he starts moving, you literally can’t look away.

As main dancer, he is responsible for some of D-ONE’s most technically demanding choreography.

He debuted with D-ONE when the group first performed in Japan on November 26, 2022.

Jaehoon’s zodiac year is the Rat, known for quick thinking, adaptability, and charm.

Fans have noted his ability to seamlessly switch between powerful vocals and intricate dance moves within the same performance — a skill that takes years to develop.

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Hyunwoong — The Rapper with the Pen and the Flow 🎤

Hyunwoong (김현웅, Kim Hyun Woong) is the main rapper of D-ONE and one of the group’s most experienced performers. Born on February 8, 1998, this Aquarius made his industry debut way back in 2017 — making him one of the most seasoned members with real depth of experience behind him.

He debuted in the K-pop industry in 2017 as a member of boy group 14U — years before D-ONE even existed.

Hyunwoong is a lyric writer — he co-wrote the lyrics for D-ONE’s very first single, “Torch.”

He also has writing credits on 14U’s “Don’t Be Pretty” and multiple 2Z tracks including “1822,” “Roulette,” “My 1st Hero,” “Keep The Promise,” and “25.”

His hobbies include exercising, playing basketball, and writing song lyrics — basically, he’s constantly training his body and his mind.

Hyunwoong is a former member of 2Z (2019–2020), a group he joined after 14U disbanded.

He spent time with the GOGO2020 firm from 2019 to 2020 before continuing his career path.

His role models are his own parents — a surprisingly wholesome answer from someone with his level of confidence on stage.

Hyunwoong’s specialties include dancing, rapping, and acting, which makes him one of the most multi-talented members of the group.

He was the first member revealed for D-ONE on October 5, 2022 — meaning the public met him before the group even had a name.

Fun nickname alert: he’s known as “Haribo” by those close to him because of his well-known love of gummy candies!

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Ihwa — The Vocal and Dance Powerhouse 🌸

Ihwa (이화) brings the emotional depth to D-ONE’s performances. As the main vocalist and main dancer, he represents the artistic heart of the group. Born on December 6, 1996, this Sagittarius is actually the oldest member by birth year — and carries that quiet authority gracefully.

Ihwa was revealed as D-ONE’s fifth pre-debut member on October 10, 2022 — just days before Jaehoon’s reveal.

Although he’s the oldest by birth year (born 1996), he doesn’t act as the group’s leader — that role belongs to Jaehoon.

His position as both main vocalist AND main dancer means he carries the heaviest performance workload in the group.

Ihwa is a Sagittarius, a sign known for passion, honesty, and an adventurous spirit — all qualities fans see in his stage performances.

He began his entertainment career around 2020, giving him solid training experience before D-ONE’s debut.

Ihwa’s vocal style tends to carry the emotional weight of D-ONE’s ballad sections, with a tone that stays with you long after the song ends.

His name “이화” (Ihwa) is quite uncommon as a stage name in the K-pop industry, making him instantly distinctive.

Among fans, Ihwa is often praised for having one of the most expressive faces during live performances — every emotion reads clearly from the stage.

He promotes actively in both Korea and Japan, navigating the bilingual demands of the group’s dual-market promotions.

Ihwa’s dance precision combined with his vocal range makes him one of the rare K-pop performers who can command attention whether he’s singing a quiet note or hitting a complex move.

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Sejin — The Gamer, the Jokester, and the Soccer Star ⚽

If you’re looking for the member who keeps D-ONE’s group chat the most entertaining, Sejin (이세진, Lee Se Jin) is probably your guy. Born on July 22, 1999, this Cancer is a sub-vocalist, dancer, and the member with perhaps the most layered backstory in the group — from multiple pre-debut groups all the way to military service and back.

Sejin joined D-ONE on November 27, 2023 — making him the newest addition before Jooyoung came along in 2025.

He is a former member of 14U (alongside D-ONE’s own Hyunwoong), and was also part of the Lucky sub-unit within that group.

Sejin enlisted in the military on October 14, 2021 and completed his service before joining D-ONE.

He has two pet poodles named Sarang (사랑, meaning “love”) and Somang (소망, meaning “hope”) — and yes, they have their own Instagram account.

His hobby? Cracking dad jokes. He is reportedly the group’s unofficial comedian and pun master.

Sejin enjoys playing League of Legends in his downtime — a very relatable pastime for many K-pop fans.

His favorite color is white and his favorite number is 0.

Sejin’s shoe size is 250 mm, and his role models include NCT and singer Yoon Jungshin.

He relieves stress by listening to music — simple but effective.

Sejin’s self-described specialty is soccer, and he’s said his main charm point is his “reverse charm” — meaning he seems one way at first glance, but surprises you once you get to know him.

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Han — The Quiet Vocalist with Hidden Depths 🎵

Han (한) may be one of the more mysterious members of D-ONE in terms of publicly available information, but what fans know for sure is that his vocals are essential to the group’s overall sound. He was revealed as D-ONE’s fourth pre-debut member and has been with the group through its most formative moments.

Han was the fourth member revealed for D-ONE, announced on October 9, 2022 — alongside Ihwa’s reveal.

He has been described by fans as the group’s most mysterious member, which only makes everyone want to know more about him.

Han began his training journey around 2020, building skills before D-ONE’s debut.

His single stage name “Han” is short, punchy, and incredibly memorable — standing out in a sea of multi-syllable K-pop names.

As a vocalist, Han contributes to the harmonic depth of D-ONE’s music, particularly on their more emotional tracks.

Fan communities often describe Han as the member who shows the biggest growth between early content and recent performances.

He has been present for every major D-ONE Japan live event, building a dedicated Japanese fanbase alongside the rest of the members.

Han’s low-key personality off stage contrasts with the energy he brings during live performances — a favorite quality among fans who love his on-stage transformation.

D-ONE has always promoted primarily in Japan, meaning Han has strong ties to the Japanese K-pop fanbase.

As more content from D-ONE drops in 2026, fans are eagerly watching to see more of Han’s individual personality shine through in vlogs, variety appearances, and member content.

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Jooyoung — The ENFP Maknae Who Lights Up Every Room ✨

Last but definitely not least, Jooyoung (최주영, Choi Jooyoung) is the youngest member (or maknae) of D-ONE. Born on January 7, 2002, this Capricorn is full of energy, personality, and ambition — fitting perfectly for someone with an ENFP personality type. He officially joined D-ONE in February 2025, making him the newest face in the lineup.

Jooyoung officially joined D-ONE on February 17, 2025, announced by Mainbase Entertainment after he completed his training.

He is the group’s youngest member (maknae), born in 2002 — making him the baby of a group where the oldest member was born in 1996.

His MBTI type is ENFP — known as “The Campaigner.” ENFPs are enthusiastic, creative, and genuinely warm people. This is said to match Jooyoung’s personality very well.

Before joining D-ONE, Jooyoung was introduced as a member of the pre-debut group IB147 in 2023, which later became inactive before officially debuting.

His favorite colors include blue, pink, black, and white — a wide range that fans say reflects his flexible and expressive personality.

As the maknae, Jooyoung tends to receive a lot of affection and teasing from the older members — a classic K-pop group dynamic that fans love to watch unfold.

Even as a new member, Jooyoung already has experience in training for performance, having gone through a pre-debut group process before finally landing in D-ONE.

His birthday falls on January 7, making him a fellow Capricorn alongside leader Jaehoon — fans love pointing out this connection between the oldest and youngest members.

Jooyoung has quickly become a fan favorite since joining, with his bright energy and enthusiastic participation in group content.

As the member with the most recent debut, fans are particularly excited to watch Jooyoung develop and grow alongside the more experienced members of D-ONE in 2026 and beyond.

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Achievements

D-ONE may be considered an underrated K-pop group in some circles, but their achievements tell a story of genuine persistence and cross-cultural appeal:

• First Korean and Japanese Dual-Market Group: D-ONE is one of the few 5th generation K-pop groups to launch their career simultaneously building both a Korean and Japanese fanbase from the very beginning, without waiting for domestic success first.
• Debut Single “Torch” (2022): The group made their Korean debut on November 26, 2022, with a single whose meaning — “to light a fire and bring warmth back to a cold relationship” — set the emotional tone for the entire D-ONE brand.
• Japanese Debut with “One Dance” (2023): Their formal Japanese debut single released on August 27, 2023, marked a major milestone for the group’s cross-border ambitions.
• D-ONE Japan Live 2023 – Chapter 2: Spring Memories: The group successfully held a live event series in Japan, demonstrating real drawing power with Japanese audiences.
• Lineup Evolution and Resilience: Despite losing a member and going through two additions, D-ONE maintained activity and fan engagement — a testament to the loyalty of the Diary fandom.
• Jooyoung’s Addition (2025): The arrival of the new maknae gave the group a fresh boost of energy heading into 2025 and 2026.
• Active on Multiple Platforms: D-ONE consistently maintains presence on YouTube, TikTok, Instagram, and X across both Korean and Japanese accounts — a professional multi-platform strategy that reflects growing industry support.

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Discography and Music Videos

D-ONE’s music catalog reflects their dual-market focus, with releases in both Korean and Japanese. Here’s a look at their key releases:

Korean Releases

Japanese Releases

Live Releases / Special Content

For Fans: D-ONE’s discography is still growing in 2026, and their focus on the Japanese market means new singles and live content continue to roll out. Follow their official YouTube channel (D-ONE OFFICIAL) and Japanese Instagram (@done_officialjp) for the most up-to-date releases and music video drops.

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Live Performances and World Tours

D-ONE built their career on live performance from day one — literally. Their very first group event was a live showcase in Japan on November 26, 2022, the same day as their Korean debut. This shows you just how central live performance is to D-ONE’s identity as a group.

Tour and Live Event History + 2026 Schedule

For International Fans: As of 2026, D-ONE’s live activities are primarily focused on Japan and South Korea. If you’re hoping to catch them at an international tour stop, keeping an eye on their official accounts is the best way to stay ahead of any new announcements. The group’s growing Diary fandom is a big reason to believe expanded tour dates could be on the horizon.

What to Expect at a D-ONE Live Show

If you’ve never seen D-ONE perform live, here’s what fans consistently say makes their shows special:

• High-energy choreography led by main dancer Jaehoon and Ihwa, with precise synchronization across the whole group
• Emotional vocal moments where Jaehoon and Ihwa’s voices carry the weight of their most personal songs
• Fan interaction that feels genuinely warm — D-ONE are known for making each audience feel seen
• Bilingual performances in both Korean and Japanese, which creates a unique atmosphere at their Japan shows
• Intimate venue vibes — since D-ONE often performs in smaller live venues, the connection between the group and the fans is real and close