Meet HI-BOYZ, the sensational K-pop boy group from the “Resident Playbook” K-drama. While they might not be real, they have successfully charted Korea’s top music platforms. And despite never debuting in real life, fans have already called for a reunion. Beyond the K-drama, HI-BOYZ has become a fully-fledged K-pop boy group with real members as well as a fabulous fandom phenomenon, and we’re here to give you the complete profile database!
HI-BOYZ K-pop Boy Group: Complete Profile Overview
- Group Name: HI-BOYZ
- Type: Fictional K-pop Boy Group
- Origin: tvN K-drama “Resident Playbook” (2025)
- Debut Date: February 4, 2011
- Disbandment Date: December 28, 2013
- Years Active: 2011 – 2013
- Fandom Name: Hello Girls
- Fandom Chant:
- Fans: “Hi~ My Boys!”
- HI-BOYZ: “Hi~ Hello Girls!”
- Official Colors: Sky Blue and Vanilla Cream
- Genre: Early 2010s-style upbeat K-pop, with retro charm and emotional warmth
- Signature Track: “When the Day Comes” (OST for Resident Playbook)
- OST Release Date: May 11, 2025
- Performance Video Release: May 12, 2025 (Stone Entertainment YouTube)
- Notable Fictional Achievement
- First music show win: June 9, 2012 (nominated on June 2)
HI-BOYZ rose during the golden age of second-gen boy groups, delivering bright pop vocals, coordinated group choreography, and polished visuals. Their signature song “When the Day Comes” captures the warmth and energy of early 2010s K-pop, pairing melodic sincerity with clean, catchy hooks and emotional undertones.
For the style choice of the profile and members, HI-BOYZ echoes influence mainly from the BOYFRIEND K-pop group. Yet, you can also see a bit of a blend with INFINITE, B1A4, and early BTOB. This style offers fans a feeling of homecoming in a modern landscape of genre experimentation.
Though their time was short, HI-BOYZ left a lasting impression. And they made it all the more impactful by their mysterious disbandment and unexpected viral comeback over a decade later.
HI-BOYZ Members Complete Profile
Now, let us discuss the complete profile of HI-BOYZ members who went public: Um Jay, D.I (Visual), and Top Key.
Um Jay (엄제이), Real Name: Um Jae Il
- Position: Leader, Main Vocal
- Fictional Portrayed By: Kang You-seok
Firstly, we have the emotional anchor of HI-BOYZ, Um Jay. With real name Um Jae Il, he is remembered for his sincerity, soft power, and comforting stage presence. His leadership was marked by gentle charisma and heartfelt vocals, earning him a quiet but loyal fanbase.
In the narrative of “Resident Playbook,” Um Jay retires from idol life to pursue medicine, but his karaoke performance of “When the Day Comes” brings his past—and the group—back into public memory.
Bin (빈) = D.I
- Position: Sub-vocalist, Lead Dancer, Visual
- Fictional Portrayed By: Soobin (TXT)
Known for his graceful movements and calm elegance, D.I added visual balance and softness to HI-BOYZ. His gentle tone and stage composure brought emotional contrast to the group’s upbeat tracks.
In the revived music video and live content, D.I perfectly embodies the visual nostalgia of 2011’s idol archetype.
Top Key (탑키)
- Position: Main Rapper, Lead Dancer, Center
- Fictional Portrayed By: Yeonjun (TXT)
HI-BOYZ’s standout performer and fan-favorite, Top Key was the spark behind the group’s on-stage intensity. With confident charisma, expressive rap delivery, and a signature wink that lives rent-free in fan edits, he became the group’s “it boy.”
Even in 2025, fans still chant his name. Not only that, but many also credit Top Key as the main reason Hello Girls refused to move on after disbandment.
Note: Leeho, Sungtan, Junhee, and Million were recently revealed as additional members of HI-BOYZ, but no further information about their roles or portrayals has been disclosed as of now.
HI-BOYZ K-pop Discography Profile
“When the Day Comes” – OST for “Resident Playbook”
The group’s only hit track, “When the Day Comes,” became an overnight sensation—not only inside the drama, but also in reality.
- Official Release Date: May 11, 2025 (as OST for Resident Playbook)
- Voiced by: All five members of TXT (Yeonjun, Soobin, Taehyun, Beomgyu, Hueningkai)
- Genre: Retro-inspired pop with clean vocals, sentimental lyrics, and energetic choreography
- MV Cast: Kang You Seok, Yeonjun, Soobin
- Chart Rankings (Post-OST release):
- #29 on Bugs
- #30 on FLO
- #49 on Genie
- #73 on MelOn
Despite being released as a fictional group’s track, “When the Day Comes” charted across multiple platforms, prompting debates about its authenticity, nostalgic charm, and even industry direction for TXT.
HI-BOYZ K-pop Boy Group Members: In-Drama Lore & Impact
HI-BOYZ was introduced through the 2025 tvN drama “Resident Playbook,” a spin-off of “Hospital Playlist.” The K-drama’s storyline reveals that resident Um Jae Il (Kang You Seok) was once an idol, the leader of HI-BOYZ, who left the industry after the group disbanded.
In Episode 9, his karaoke rendition of “When the Day Comes” sparked viral attention when a retro-style MV played behind him, revealing fellow former members portrayed by TXT’s Soobin and Yeonjun.
The inclusion of real idols portraying fictional roles—and performing the actual OST—has successfully blurred the boundary between scripted lore and real-world fandom.
Fans have now adopted HI-BOYZ as if they were a lost second-gen group rediscovered through K-drama magic and urge for an immediate reunion.
Real-Life Reception and Viral Impact
While HI-BOYZ is fictional, its reception has been anything but.
- Fandom Revival: “Hello Girls” became an actual online community complete with slogans, fancams, memes, and fake comeback demands.
- Viral Fan Theories: Social platforms exploded with mock theories about why HI-BOYZ disbanded, who “Top Key” really was, and whether the group could be revived.
- Chart Performance: The OST’s rise on real Korean streaming charts blurred the line between parody and genuine public love.
- Dance Challenges: Kang You Seok and Han Ye Ji (Kim Sa Bi) participated in the “When the Day Comes”challenge, cementing the song’s memeable charm.
- Meta-Commentary: Fans expressed that TXT’s success with this fictional concept highlighted frustrations with HYBE’s real-world musical direction for the group.
Hi-BOYZ Special Stage on M COUNTDOWN Ep.889
The Fictional K-pop Boy Group That Breaks the Fourth Wall
HI-BOYZ may have never held a real showcase or fan sign, but their impact is anything but imaginary. Through a single song, one MV, and a drama moment that caught lightning in a bottle, they’ve reawakened the emotional power of K-pop’s earlier years.
What started as a karaoke scene has now become a cultural reference—one that feels oddly more sincere than many real promotions today.
Finally, for fans still holding out hope: no, a HI-BOYZ reunion isn’t on the schedule. But then again, neither was their comeback. And look how far that went.
Stay tuned as we continue documenting the most creative intersections between K-pop, K-drama, and global fan culture.
If you’re a Hello Girl at heart, don’t worry, we see you. And if you’re still rewatching that karaoke scene, well, please know that you’re not alone.
Hi~ My Boys!
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