Kenshi Yonezu’s IRIS OUT on Spotify’s 2026 Mid-Year Charts

In Spotify Japan’s first-half 2026 rankings announced on July 1, 2026, Kenshi Yonezu’s “IRIS OUT” ranked No. 1 among the most-streamed songs inside Japan and No. 2 in the category of “most-streamed domestic songs overseas.” First place in the overseas category went to King Gnu’s “AIZO.” Cumulative worldwide streams for “IRIS OUT” surpassed 274 million, with listeners outside Japan accounting for more than half of the total (centered in the United States, South Korea, and Mexico). Rather than being “the most-streamed Japanese song overseas,” it was the most-streamed song in Japan and the second most-streamed Japanese song abroad (announcement verified on September 24, 2026).

Spotify Japan 2026 first-half rankings | “IRIS OUT” takes No. 1 at home and No. 2 overseas

From the first-half rankings published by Spotify Japan on July 1, 2026 (tracking period: January 1 to June 24, 2026), the entries involving these two songs are as follows.

Kenshi Yonezu had already established an international profile through global hits such as “KICK BACK,” which earned Gold certification from the Recording Industry Association of America (RIAA). One detail to keep in mind when reading the numbers is that the 274 million figure includes streams inside Japan and counts cumulative plays since the song’s September 2025 release. First-half rankings are decided by plays between January 1 and June 24, 2026, and the overseas category counts only plays outside Japan. There is no contradiction between “IRIS OUT” having a larger cumulative total than “AIZO” (released in January 2026) and “AIZO” ranking higher in the first-half overseas category.

The two songs form a clear contrast. “IRIS OUT” took No. 1 in the domestic song rankings while also drawing strong listenership in the United States, South Korea, and Mexico to push its overseas share past 50%. “AIZO” placed No. 6 in the domestic song rankings, yet gathered enough support abroad—led by the United States—to take No. 1 in the overseas category. The most-streamed song in Japan and the most-streamed Japanese song overseas were two different tracks, and both were anime theme songs (“IRIS OUT” for Chainsaw Man – The Movie: Reze Arc, and “AIZO” as the opening theme for Season 3 of the TV anime Jujutsu Kaisen, “The Culling Game Part 1”). That is the core takeaway from the first-half figures.

Why the song crossed borders | Negative space and refrain in its sound design

From a musical standpoint, a major factor behind the international reach of “IRIS OUT” is its radical aesthetic of subtraction. Recent Japanese pop and anime theme songs have often been defined by densely packed chord progressions, constantly shifting beats, and dozens of stacked vocal and synthesizer layers. While that high-density approach excites dedicated domestic listeners, it can easily cause ear fatigue for casual listeners abroad.

The sound design presented on “IRIS OUT,” by contrast, strips away excess weight. Its backbone consists of a restrained, minimal kick and bassline paired with a dry snare in an open acoustic space. Unnecessary rapid-fire chordal accompaniment is cleared out, placing unmistakable moments of silence—negative space—between the notes. Thanks to that architecture, what leaps cleanly into the listener’s ear is the grain of Kenshi Yonezu’s voice and the groove of the repeating refrain. As we explored in our Introduction to Alternative Rock (Reflections on Subtraction and Negative Space), the structural skeleton that remains after ornament is stripped away is what gains universal strength across genres and borders.

For overseas listeners who do not process the Japanese lyrics directly as verbal meaning, the vocal is perceived as an acoustic instrument spinning out a melody. Avoiding overcrowded syllables and setting a simple, hypnotic melodic refrain in place establishes a pure sonic pleasure principle that crosses the language barrier. Precisely because empty space is left open, the minimal beat placed inside it projects intense presence. That active use of “unplayed notes” is what allowed the track to sit so naturally in the ears of listeners accustomed to overseas alternative and minimal beat music.

Contrast with overseas No. 1, King Gnu’s “AIZO” | A high-density track took the top spot abroad

What cannot be overlooked here is that No. 1 in the overseas category went to King Gnu’s “AIZO.” The defining hallmark of King Gnu’s music lies in its high-density arrangements: tightly calculated classical music theory, explosive rock dynamics, and melodies locked closely to the cadence of the Japanese language.

It is easy to assume that such a densely packed song is an “art of addition” that works best for listeners who share the Japanese linguistic context. Yet in the first-half figures, “AIZO” stayed at No. 6 inside Japan while ranking No. 1 in streams overseas. The hypothesis in the previous section—that negative space is what carries a song across borders—cannot be proved by this ranking alone. Spotify’s announcement links the overseas spread of “AIZO” to the popularity of Jujutsu Kaisen, noting that “SPECIALZ,” the opening theme for Season 2 (“Shibuya Incident”), also resurfaced at No. 8 in the same overseas category as an example of related songs spreading worldwide alongside an anime franchise.

“IRIS OUT” is likewise the theme song for a theatrical anime film, and the same overseas category includes “KICK BACK,” which Yonezu wrote as the opening theme for the TV anime Chainsaw Man, at No. 7. Crediting overseas listenership solely to audio production would be one-sided; the popularity of the anime works serves as a wide front door. As I read it, the anime opens the door, and the sound design helps decide whether listeners keep hitting replay once they are inside. Pushing through with sheer density on “AIZO” and drawing listeners in through negative space on “IRIS OUT” represent two opposite musical architectures gathering overseas streams after entering through the same anime doorway.

Loudness and dynamics in the streaming era

The spread of subscription streaming services has also brought a decisive shift to mixing and mastering design. During the heyday of the CD “loudness war,” the standard move was to use maximizers to push overall volume to the very ceiling of the waveform, crushing dynamic range in the process. Today, however, major streaming platforms led by Spotify automatically apply loudness normalization (around -14 LUFS as the reference standard on Spotify). We cover the technical details behind this specification in Loudness Normalization Specifications in the Streaming Era.

Under these conditions, an overly brickwalled master has its overall gain turned down automatically by the platform’s algorithm. As a result, tracks trapped in the loudness war end up sounding flat and lifeless, paradoxically coming across as quieter than their neighbors. Conversely, a master that preserves the dynamic swing between peaks and valleys and leaves generous headroom for the low-end kick and bass keeps its lively punch even after normalization is applied.

The mastering on “IRIS OUT” is built on engineering that understands this streaming environment inside out. By avoiding excessive compression and leaving transients clean, it reproduces a solid low-end core and an open top end regardless of the playback device—whether on a smartphone, wireless earbuds, or full-scale audio speakers. From an audio-quality standpoint as well, that technical foundation keeps the track from getting buried on playlists around the world.

How negative space builds durability for repeat listening

On streaming platforms, the biggest key to growing play counts is how often listeners put a track on repeat—in other words, the song’s durability. A track that overwhelms you on the first spin but tires your ears out through sheer information overload is poorly suited to everyday loop playback. To be played dozens or hundreds of times while working, commuting, or unwinding, a song needs breathing room that does not crowd the listener’s awareness.

Analyze the arrangement of “IRIS OUT” from intro to outro, and you find that instrument placement across frequency bands is tightly controlled. Decorative phrases that would clash with the vocal in the midrange are kept to a minimum, while generous space is left open across the left-right stereo field. That open airflow lowers ear fatigue during long listening sessions and creates the quiet pull that makes listeners hit repeat without thinking about it.

As a songwriter, Kenshi Yonezu began his career in Vocaloid culture, known for ultra-fast, ultra-dense songwriting. The fact that at a mature stage of his career he is deliberately stripping notes away and drawing closer to the aesthetics of ambient and alternative music points to one compelling destination for contemporary pop: defining space not by packing sounds in, but by the notes left unplayed. The record set by “IRIS OUT”—No. 1 in Japan and No. 2 overseas—shows that a song built in that direction can become part of everyday listening both at home and abroad.

Further reading: Loudness Normalization Specifications in the Streaming Era | The End of the Loudness War and Dynamics

Further reading: An Introduction to Alternative Rock — The Aesthetics of Subtraction and Negative Space

Further reading: Sakanaction’s Release Architecture | Where Physical Media and Streaming Stand Today