YOASOBI knows how to go viral. That doesnt mean they make music for TikTok.

On paper, there is very little about " Idol " that sounds engineered for the internet.

YOASOBI 's 2023 hit, written as the opening theme for the anime Oshi no Ko , is musically restless.

Over the course of less than four minutes, it ricochets between glitchy pop, rap, choral flourishes, and something much darker, while vocalist ikura switches between voices with almost theatrical agility.

It doesn't exactly sound like a song constructed around the neat, repeatable 15-second snippet that has come to define the TikTok era .

And yet the internet couldn't get enough of it.

SEE ALSO: YOASOBI makes maximalist pop with minimal tech "Idol" quickly escaped the orbit of Oshi no Ko .

With over 689 million views on YouTube and 588 million streams on Spotify, it became a dance, a cover, an edit, a challenge — the kind of song you could encounter online without ever knowing the anime that inspired it.

For YOASOBI, a duo whose music has always been inseparable from the internet, it was perhaps the ultimate example of what can happen to a song once they let it go.

But don't mistake that virality for a formula .

Ayase, YOASOBI's producer and songwriter, has little interest in writing for the algorithm.

"I don't want to get in a situation where I'm thinking about that with intention," Ayase told Mashable through an interpreter, referring to the pressure to build songs around moments that can be easily clipped or shared online.

In Japan, he said, it's become increasingly important for a song's success that it can circulate on TikTok, inspire a dance, or become a meme.

He understands the commercial logic.

He just doesn't personally subscribe to it.