When you boot up Trek to Yomi, a title card appears alongside a credit reading ‘a game by Leonard Menchiari and Flying Wild Hog.’ Years before the Polish studio behind the Shadow Warrior reboot series began to collaborate on the project — before Devolver Digital took an interest as publisher — Trek to Yomi was one man’s love letter to the black and white samurai films of Akira Kurosawa. Over the course of its development, the ambitious action game took on many partners but stuck to the original promise of authenticity.

As early as 2019, Menchiari was already beginning to figure out what he wanted Trek to Yomi to sound like. That year in Tokyo, he first met with Cody Matthew Johnson and Yoko Honda, the collaborators that would eventually become the game’s composers.  Honda, the game's music director, reflects on this first encounter.

“I was there since the early stages of conception of the game, not necessarily as a recruited music director or composer,” Honda recalled. “Cody [Matthew Johnson] and I met the director Leonard Menchiari at the Tokyo Game Show in 2019 and I was determined that I wanted to be involved as soon as Leonard showed us his ideas.”

Johnson (who’s recent output includes contributions to the Devil May Cry V and Resident Evil 2 soundtracks) worked alongside Honda and a team of engineers and editors at Emperia Sound and Music to make a soundtrack that was authentic, first and foremost. Trek to Yomi employs a film grain and black and white visual filter evocative of Kurosawa’s earlier work, but the roots go much deeper than the 1940s. The game aims for historical accuracy and period authenticity with its soundscape dating back to the 17th century.

All the music in Trek to Yomi was created using instruments found in Japan in the Edo period, when the game takes place. This ambitious undertaking pushed even the two composers to the boundaries of their historical knowledge which both have in spades.

During his years majoring as a composer in undergrad, Johnson studied ethnomusicology and was inspired to explore musical worlds outside the one he grew up with. Alas, a basic familiarity with historical East Asian instruments only took him so far when it came to this project.

“I’ve always had a fierce curiosity to learn more about music across the world, so naturally I already knew of some of the well-known instruments, such as taiko drums, shamisen, and koto,” Johnson said. “There was an armada of new instruments I had never discovered before our research on Trek to Yomi. Instruments such as the kokyu (similar to its cousin, the Chinese instrument erhu), the Gagaku ensemble, shinobue, kagurabue.” All these instruments and more were used to create the dynamic soundtrack.

Honda was born in Japan and spent her childhood in the UK and the US. Her roots stretch back to the small Japanese village of Yunishigawa, where her mother’s side of the family has a nearly 1000 year history.

“Growing up as a kid, I was exposed to a lot of traditional and very rare Japanese instruments in the village, especially around the annual summer festival,“ Honda said, explaining how the local festivities taught her about her heritage at a young age. “I have a Japanese flute 'Shinobue' from the village that I occasionally play. I'm not the best flutist in the world, but I had to use it here and there.”

Although Honda was born, raised, and studied in Japan, she obviously did not grow up in the Edo era. Much of what the game depicted felt foreign to her at the start, instruments included. As a Japanese born lead on a project aiming for accuracy, she believed herself vital to the process of creating truly authentic music for the game. Honda wasn’t a lone gatekeeper, though. Devolver hired historian Aki Matsunaga to advise with development, and check that every element was as authentic and respectful as possible. This was supported by the rest of the team who, according to Honda, were viciously meticulous about the validity and legitimacy of the game. “Japanese history is long and complicated. My perspective is that I can proudly say this game was created with due respect for everyone including myself and those sensei historians.”

That aforementioned Japanese history is fertile ground for adventure in Trek to Yomi. In Japanese mythology, Yomi is the name for the land of the dead. It’s no spoiler to say the game takes you to this otherworldly realm, which was a mid-game shift the music team had to contend with.

According to Cody Matthew Johnson, the team had a ton of creative freedom in crafting how the spirit world of Yomi would sound, both in terms of instrumentation and tone setting. The real challenge was how to represent the abstract, mysterious nature of the depths of Yomi without breaking the rules the composers had set for themselves to begin with.

“Yomi is a shared mythology between many cultures in East Asia, with strong influences from Shintoism,” Johnson said, “so we introduced some elements that were “extra-Edo”, extending into surrounding cultures. In Yomi, you can start to hear Chinese instruments like Erhu, Zhonghu, and Gaohu, Tibetan singing bowls and Monk voices.”

Taking from the rich shared mythology allowed Johnson to bend the rules by using contemporaneous instruments from other parts of Asia in the 17th century. To create the otherworldly sound in these parts of the game, Johnson had to turn to more modern influences.

“To acquire a special sound for Yomi, I pulled out all of my influences from industrial music production and sound design to treat and process these organic sound sources,” Johnson explained. “We recorded all of the instruments in the game at as high fidelity as possible so as I started to mangle, smear, stretch, and distort the recordings, they retained as much detail and frequency response as possible.”

Due to how closely it wears its influences on its sleeve, Trek to Yomi is undoubtedly going to face scrutiny. Honda is well aware that respect is an important part of the process of a mostly European team making a game emulating Japanese cinema, and by extension Japanese history. She faced a crisis of authenticity versus tonality nearly every day during the production of Trek to Yomi. This isn’t an uncommon friction point in Honda’s line of work. In fact, in her years composing for games and movies, she has found it to be a source of what she lovingly refers to as her paranoia. This primed her for the challenges that came with making sure the Trek to Yomi score both sounded authentic and used authentic sounds.

“I was supposed to write a theme for a pastoral village where the so-called commoners lived,” Honda describes composing one particular piece of Yomi’s music. “I found a Japanese flute that was sonically perfect to describe the scene. The problem was that this particular flute was meant to be used by upper class people in religious ceremonies. Dare I use a ‘commoners' flute’ that sounds less authentic, to stick with our pursuit of ‘writing everything traditionally’, or use the ‘upper class people flute’ that sounds closer to what we would have heard back then?”

When it comes to representation, authenticity and respectfulness, Honda admits she was perplexed and sometimes struggled to even explain the minutiae of some of these dilemmas to her teammates. Ultimately, she said, "If anything, my paranoia was something I had brought to the team that, more or less, affected everyone on the music team at a certain point during development... I think it helped shape this game and soundtrack to be as respectful as possible."

[Updated 5/13/21 to expand on final quote.]