YOASOBI Turned a Constraint Into the Biggest J-Pop Song in History
It’s 12:45 AM. YOASOBI’s “Yoru ni Kakeru” floods my room while I’m grinding away at Maliketh in Elden Ring, sipping champagne. My gameplay keeps mimicking the flow of the music instead of Maliketh’s dance. I die for the hundred-thousandth time and pause.
There’s something about this duo that gets under your skin. The melodies carry you through emotional highs and lows in ways that feel deliberate, almost engineered — but never clinical. And behind every song is a creative decision so counterintuitive it should have killed their career before it started.
Every YOASOBI song begins with a written story. Not a vibe. Not a mood board. A literal short story or novel that they adapt into music. That’s not a gimmick. That’s the whole product. And it’s the reason they made history.
The Commission That Changed Everything
April 2023. Manga author Aka Akasaka — the mind behind Kaguya-sama: Love Is War — has a new anime coming: Oshi no Ko, a story about the dark machinery behind Japan’s idol industry. He needs an opening theme. He doesn’t just commission YOASOBI to write a song. He writes them a short story.
That’s how YOASOBI works. Always has. But this brief was different. Akasaka’s story was specific: the hidden contradictions of the idol world, the performance of perfection, the ugliness beneath the sparkle. He handed them emotional architecture, not a vague ask.
Producer Ayase and vocalist Ikura took that story and built “Idol” — a track that shifts from saccharine idol-pop to a dark hip-hop bridge to an anthemic chorus, mirroring the story’s own journey from surface-level charm to disturbing truth. The music doesn’t just accompany the narrative. It IS the narrative, translated into sound.
“Idol” debuted at #1 in Japan. Then it did what no Japanese song had ever done: it climbed to #1 on the Billboard Global chart (excluding U.S.) and hit #7 on the Global 200. Its music video became the fastest by a Japanese artist to reach 100 million YouTube views.
The biggest J-pop song in history came from a constraint: start with someone else’s story.
The Origin: Novels Into Music
YOASOBI didn’t arrive at this process by accident. It was the founding premise.
In 2019, Sony Music approached producer Ayase with an unusual pitch: create songs based on short stories submitted to their online literary platform, Monogatary. Ayase had been uploading Vocaloid tracks online — instrumental electronic music performed by digital voices. He was a producer without a vocalist.
He found Ikura (real name Lilas Ikuta) on Instagram. Not through an audition. Not through a label. He was captivated by the warmth in her voice from clips she’d posted online. In October 2019, they quietly formed YOASOBI — a name that translates to “nightlife” in Japanese. The project was literally their after-hours creative playground, a side gig alongside their separate careers.
In November, they uploaded their debut track “Yoru ni Kakeru” (Racing into the Night) to YouTube. It was an adaptation of a short story about love and death submitted to the Monogatary platform. The music video started racking up millions of views within weeks.
By the end of 2020, “Yoru ni Kakeru” was the #1 song of the year in Japan and the first song ever certified Diamond for streaming. All of this happened without a single CD release. YOASOBI was digital-native from birth — thriving on YouTube and streaming alone.
The constraint — novels into music — wasn’t holding them back. It was doing the opposite. Every song came pre-loaded with emotional stakes, character arcs, and narrative tension. Other artists had to invent those from scratch. YOASOBI had them handed to them on paper, then translated them into sound.
How the Constraint Became the Product
Here’s what makes YOASOBI’s model worth studying: the brief IS the product.
Most artists start with a feeling and work outward. YOASOBI starts with a story — a specific, authored narrative with characters, conflict, and resolution — and works inward. The story constrains every musical decision: tempo, key changes, vocal delivery, arrangement. “Idol” shifts genres mid-song because Akasaka’s story shifts emotional registers. The music follows the narrative, not the other way around.
This is what great discovery looks like in product work. Not “go build something cool.” Not “explore the space.” A specific brief from someone who understands the problem deeply — your author, your user, your domain expert — that gives you clarity of purpose before you write a single line of code. Or a single note.
And the brief came from a collaborator, not from within. Akasaka wasn’t part of YOASOBI. He was an external creative partner with deep domain knowledge (he’d spent years writing about performance culture in Kaguya-sama) who handed them the emotional foundation for their most ambitious work. The best product moments often come from this dynamic: the PM who listens to the user who truly knows the problem, and then translates that knowledge into something the user couldn’t have built alone.
YOASOBI evolved the model over time without abandoning it. In 2022, they collaborated with four award-winning novelists for the Hajimete no (The First Time) project — each author writing stories about first experiences, each story becoming a song. In 2020, they adapted the manga Blue Period into “Gunjou.” In 2021, they scored the anime Beastars. The source material changed. The constraint held.
From a side project uploading tracks on YouTube to headlining arena tours and topping global charts — the constraint scaled with them.
The Product Lessons Hiding in the Music
Your constraint is your differentiator. Every artist has access to the same instruments, the same production tools, the same streaming platforms. YOASOBI’s “novels into music” rule is what makes them impossible to copy. In product, the constraint you impose on your team — the focus, the scope, the non-negotiable design principle — isn’t a limitation. It’s what keeps you from building the same thing as everyone else. The team that says “every feature must solve a problem we can name” will outship the team with infinite optionality.
The brief IS the product. When Akasaka wrote that short story for YOASOBI, he didn’t give them a mood board or a list of themes. He gave them a narrative with specific emotional beats: the idol’s public smile, the private darkness, the eventual reckoning. That level of specificity in a brief produces specificity in the output. Vague briefs produce vague products. If your PRD could describe any product in your category, it’s not a brief — it’s a wish.
Commission the expertise you don’t have. Ayase is a brilliant producer. Ikura is a remarkable vocalist. Neither of them is a novelist. Instead of writing their own stories (which they could have done), they partnered with authors who brought depth they couldn’t manufacture. The best PMs do this instinctively: they find the user, the domain expert, the researcher who knows things the team doesn’t, and they build from that knowledge rather than their own assumptions.
Start as a side project. Stay hungry. YOASOBI’s name means “nightlife” because it started as an after-hours experiment. The side-project energy — the freedom to try weird things, the absence of institutional pressure, the willingness to upload a track and see what happens — is what produced “Yoru ni Kakeru.” That energy doesn’t have to disappear when the project scales. Protect it. The thing that made you matter when nobody was watching is the thing that will keep you relevant when everyone is.
YOASOBI didn’t break records because they had more talent or better marketing or a bigger budget. They broke records because they had a constraint — every song starts with a story — and they held it long enough for it to become their identity.
The brief isn’t the thing that slows you down. It’s the thing that tells you where to go.
Race into the night. Start with the story.