LIGHTSUM Nayoung Covers YOASOBI's Global Mega Hit Under Seoul's Night Sky

When LIGHTSUM member Nayoung decided to cover YOASOBI's "Yoru ni Kakeru" — known in Korean as "밤을 달리다 (Run Into the Night)" — she didn't record herself singing in a studio. She took the song outdoors, to the heart of Seoul after dark, filming against the city's most celebrated nocturnal landmarks to match the music's atmospheric midnight energy. The result is a cover video that has quickly drawn attention for both its visual polish and its vocal confidence.

Released on May 19 through LIGHTSUM's official social media channels, the clip shows Nayoung performing against the lit-up skyline near Namsan Tower and the flowing arc of the Hangang Bridge — two locations that rank among Seoul's most iconic nighttime views. The choice of setting was deliberate. A song called "Run Into the Night" practically demands a backdrop like this, and Nayoung committed to the concept fully, letting the city's glowing infrastructure become as much a part of the performance as her own voice.

The Song Behind the Cover

"Yoru ni Kakeru" is not an ordinary J-pop track. Released in 2019 as the debut single from YOASOBI — the Japanese music duo comprising composer Ayase and vocalist ikura — the song was adapted from Hoshi Mayo's short story "The Temptation of Thanatos," a dark, emotionally complex narrative about love and loss. Despite its heavy source material, the song's arrangement is bright and propulsive, driven by a piano-forward melody that shifts from playful optimism to aching emotion within the span of a single verse.

By 2020, it had claimed the top spot in the Billboard Japan HOT 100 annual ranking. Since then, it has accumulated over 700 million streams on Spotify — placing it among the most-streamed Japanese songs of the digital era and cementing YOASOBI's reputation as one of Japan's most globally influential contemporary acts. When K-pop artists cover it, they are taking on something with genuine weight behind it.

The original vocal performance by ikura has set a challenging bar: her style blends an airy lightness with sudden emotional urgency in ways that are technically demanding to replicate without losing the song's essential character. Nayoung's approach is to interpret rather than imitate. Where ikura's delivery has an almost weightless quality above the beat, Nayoung's version is warmer and more grounded — her tone crystal-clear and direct rather than ethereal. The result sounds like the same song heard through a different but equally valid emotional lens.

Who Is Nayoung Within LIGHTSUM?

LIGHTSUM (라잇썸) is a six-member girl group under Cube Entertainment, one of South Korea's established mid-tier labels known for groups including (G)I-DLE, CLC, and Pentagon. The members are Sangah, Chowon, Nayoung, Hina, Juhyeon, and Yujeong. In K-pop terminology, Nayoung is often described as a "hexagonal" performer — meaning she demonstrates measurable competency across all six dimensions of idol performance: vocals, rap, dance, visuals, stage presence, and interpersonal charisma. The term is used sparingly and carries genuine weight when applied.

This cover makes the case for the label. The technical demands of "Yoru ni Kakeru" expose any weaknesses in pitch control or tonal consistency, and Nayoung navigates them cleanly. Her handling of the song's brighter melodic sections carries warmth without losing clarity, while the more melancholic passages are delivered with enough restraint to feel genuine rather than performed. What she avoids is the over-emoting that often marks idol covers of demanding songs — the tendency to push harder than the material requires to demonstrate effort. Nayoung trusts the song and lets it breathe.

Cover videos have become a meaningful format in K-pop for individual group members to establish a separate artistic identity outside the collective image. Choosing a song as globally recognized as "Run Into the Night" serves multiple purposes: it speaks to existing Korean and Japanese fans familiar with YOASOBI, while also reaching listeners who might encounter LIGHTSUM for the first time through the cover and follow that thread back to the group's main discography.

Seoul as the Third Performer

One of the more distinctive elements of this cover is how seriously the production takes its location. Seoul at night is visually spectacular in ways that many cities simply are not — the density of light along the Han River, the way Namsan Tower anchors the skyline, the reflections off the water from the bridges. Using these as the visual backdrop for "Run Into the Night" is not incidental. The city becomes a third performer in the video, its illuminated architecture providing the kind of emotional scale that the song's arrangement gestures toward but never quite articulates.

For international viewers who have not been to Seoul, the images function as a portrait of a specific kind of urban beauty — the kind that is hard to describe but immediately recognizable once you've seen it. For Korean fans, the same images carry a different resonance: these are places they know, places that hold their own memories of late-night walks and conversations, now refracted through a song about rushing toward something in the dark.

The decision to film outdoors rather than in a controlled studio environment also adds a degree of genuine atmosphere that indoor covers often lack. The slight imperfection of real locations — the ambient noise, the organic light sources, the sense of actual weather and actual space — gives the video a texture that studio shoots cannot replicate.

LIGHTSUM's Active Summer

Nayoung's cover arrives during a notably busy period for LIGHTSUM as a group. They recently performed at the opening ceremony for SBS's new variety program "열혈농구단 (Hot-Blooded Basketball Team) Season 2," adding another high-profile performance credit to their growing resume. More significantly, they have been booked for multiple university festivals across South Korea this season — a strong indicator of their rising domestic popularity.

The university festival circuit in Korean entertainment is one of the most competitive and culturally resonant performance traditions in the industry. Schools pay significant appearance fees to book artists, and the selection process is competitive and driven by genuine student demand rather than label promotion. Being invited to multiple festivals in a single season signals that LIGHTSUM has built a real and growing fanbase that extends beyond their core fandom. It is the kind of engagement that precedes a significant commercial breakthrough.

In that context, Nayoung's solo cover is well-timed. As new audiences encounter LIGHTSUM through festival appearances and variety show exposure, solo content from individual members gives those audiences somewhere to go — a more personal entry point into the group beyond the collective image. A cover video like this one says, very clearly: here is who this member is when she has the stage to herself.

What Fans Are Saying

Response to the cover has been enthusiastic across multiple fan communities. Korean fans have particularly praised Nayoung's restraint — the choice not to over-demonstrate her technique at the expense of the song's emotional integrity. Fans familiar with YOASOBI's original have noted that her interpretation is distinctive enough to stand on its own rather than simply measuring itself against ikura's version.

International fans, especially those who follow both K-pop and J-pop, have responded warmly to the cross-cultural framing of the video — a Korean idol performing one of Japan's most beloved contemporary songs against a backdrop that is unmistakably, beautifully Korean. It is a small gesture of cultural conversation that carries more meaning than it might appear to at first glance.

LIGHTSUM's activities are expected to continue through the summer season, and whether this cover signals something further for Nayoung as a solo performer remains to be seen. What is clear is that she has used it to say something specific about who she is as an artist — and that the message has landed.