YOASOBI's songs pile on bright pianos, electronic beats, and sonic surprises that seem to shift direction before you've had time to settle in. Yet the production setup behind this maximalist sound is remarkably stripped-down.

When Mashable asked the duo during a Los Angeles press day to name five pieces of technology essential to their music, Ayase struggled to come up with a fifth. "I don't really use anything other than these," he said.

The list reads like an accessible toolkit: Logic Pro for composition and arrangement, Splice for accessing a digital sound library, a high-end Sony microphone for recording ikura's vocals, and wired EarPods—yes, the older Apple earbuds with a headphone jack. The simplicity of the EarPods, Ayase explained, makes them useful rather than a nostalgic holdover.

This lean approach contrasts sharply with the complexity of songs like "Idol," the Oshi no Ko opening theme that's accumulated over 688 million YouTube views by ricocheting between musical ideas with little regard for pop convention.

Ayase's journey shaped this ethos. After pursuing rockstar dreams in a band during his teenage years, he turned to Japan's Vocaloid production scene, where a laptop and voice-synthesizing software like Hatsune Miku could serve as a complete studio. He could compose, produce, and provide vocals largely alone—a practice he's carried forward. When he began collaborating with ikura, her voice replaced synthesized vocals, but Ayase's ambition didn't scale back. His intricate melodies often sound written without concern for the physical limits of human breath, yet ikura keeps pace.

The story behind YOASOBI's sound underscores a broader truth: the tools themselves—mostly available to anyone with a laptop and internet access—aren't what define the duo's music. It's what Ayase does with them. There's no single mysterious piece of equipment responsible for the YOASOBI sound. The maximalism comes from the producer's vision, not from gear.