Born in Washington, D.C., Diana was influenced by their father, a fan of anime and manga, and grew up interested in Japanese culture.[1][2] In particular, they were greatly impressed, and influenced by Japanese music used in anime, which motivated them to pursue a singing career in Japan.
Their interest in the country was further sparked by two year-long exchanges in Japan in both high school and university.[3] Upon graduating from university, they relocated to Tokyo, Japan, to work as an Assistant Language Teacher while doing freelance narration and vocals for radio and advertisements.[4]
They began uploading covers of anime, J-pop and vocaloid songs onto YouTube and Niconico, gaining popularity and attention under their aliases Tonkhai and トンカイ.
2013–2014: Nodojiman The World, Japanese Debut and Cover☆Girl
2014–2015: Featured artist, Spinning World and Nankai! Mystery
2014 saw Diana being featured as an artist in Dohzi-T's track "Turn Me On ft. Diana Garnet", released on March 19 on his sixth studio album "T's Music".[9]
The title track of their first original single, "Spinning World", released on February 11, 2015, was used as the ending theme song for the anime Naruto: Shippuden and grew to be one of the most beloved songs to their fans.[10][11][12][13][14] As of 2024, the song has amassed more than 2 million plays on Spotify.
On February 25, Japanese rock band Flow released their compilation album Flow Anime Best Kiwami, featuring Diana on their cover track "Blue Bird ft. Diana Garnet", originally by Japanese pop-rock band Ikimono-gakari.[15] On August 15, the singer, as well as the band Granrodeo, went on to perform with the band as guest performers on their Flow World Tour 2015: Kiwami world tour finale in the Hibiya Open-Air Concert Hall in Chiyoda, Tokyo.[16]
Diana's second original single, Nankai! Mystery, was released on November 25. Its title track was chosen to be the theme song of the anime adaptation of the original light novel series Tantei Team KZ Jiken Note.[17][18][19][20]
2017–2018: Voice actor, Igo Focus, Radio host and Thank you for the Music
In 2017, Diana branched out in their engagements, appearing in many events in Japan like the KIDSTONE Summer Presentation Program[21] and stateside anime and manga conventions, like Ohayocon and Animazement, as well as on TV and in print. They also took on voice acting, narration and becoming a TV host.
In February, they first provided their voice for English-speaking roles of Joule and Lumen the double identities of the heroine of Azure Striker Gunvolt, in the English dub of the original video anime adaptation of the game, released worldwide on the Nintendo eShop.[22][23][24]
From April until March 2018, Diana was the host for the 2017 season of the long-running series Igo Focus, an establishment in the Japanese world of Go.
Since April, they have been one of the co-hosts of the educational NHK radio show "Kiso Eigo 1", a main staple among language education in Japan since its first broadcast in 1994.[26][27] As of 2024, alongside fellow co-host Chris Nelson, they possess one of the longest tenures a co-host of this radio show has ever had.
During the same time they also narrated the NHK World series "Anime Supernova", highlighting different directors in the Japanese animation industry for a global audience.[28] They also landed their first Japanese-speaking role for the dramatization of Yushi Okajima's book "Gijinka de manabo! IT Infra no shikumi", voicing the role of DBMS.
Later in the year, they provided their voice for English-speaking roles in several games, like Super Bomberman R and released their third original single, "Thank you for the Music", on November 7. The title track was chosen to be the second ending theme for the third season of the anime series "Meow Meow Japanese History".
2019–2020: Game OSTs, Hello Again and Igo no uta
2019 marked Diana's participation in original soundtracks for video games, as they performed the theme songs of the two video games Nippon Marathon, "Hyperlove Racing",[29] and Dragon Marked for Death, "Falanaja".[30]
The year also saw them venturing into acting, as they appeared in the January TV Kanagawa drama "Shiba Kōen", the February commercial short movie "Man'yō ni Ikō." for hot spring hotel chain Manyo Club and the June Line Live web drama "Shibuya Boys Scramble".
On June 5, they released their first digital single, "Hello Again", providing the first ending theme for the fourth season of "Meow Meow Japanese History".
They continued to pursue voice acting and appeared in Japanese-speaking roles in the anime series "Meow Meow Japanese History" they had previously provided ending themes for, voicing historical characters like Heian periodbuddhist monkTaihan in February, samurai Egawa Hidetatsu and legendary folk hero Ishikawa Goemon later on in June. In an English-speaking role, they voiced Sophia in the AMG Entertainment movie "Prison 13" in August.
2020 saw Diana contributing more theme songs and participating in live performances throughout the year.
On January 15, 2020, they released their fifth original single, "Igo no uta". The single contains the cooperation of several individuals: professional Go players Yohei Shimojima penning the lyrics and Asami Ueno designing the cover, singer Chris Hart composing the song with musician Paul Ballard and mangaka Nodoka Tsurimaki drawing the cover art.
They went on to perform the theme songs "Fight Yourself" for the readers theater play "Dragon Zakura~2nd season~" in January and "Here and Now" for the visual novel Caffeine: Victoria's Legacy in March, for which they also voiced the main character Eliza.
2021–2022: Further voice acting and Voice directing
In 2021 and 2022, Diana continued to voice act, lending their voice bilingually to both Japanese and English-speaking roles.
Since February, they have been voicing the Japanese-speaking role of Japanese English teacher Momo Tomozawa, a main character of the well-received Benesse franchise "Kūsō Gakuen Pantasia". They appeared in the animated Netflix series "Bee and Puppycat" as the TempBot in September.
Diana also worked as a casting director and voice-over director on several games, namely "Rival Megagun XE", "Gunvolt Chronicles: Luminous Avenger iX 2" and "Azure Striker Gunvolt 3".
In December, they voiced the Genshin Impact character Dehya in the Dillongoo Studios web anime short "Nameless Road" for MiHoYo's regular fan event "HoyoFair 2023". This marked the beginning of Diana's collaborations with Dillon Gu and Dillongoo Studios projects.
2023–2024: Continued voice acting & directing, Tie-up releases and Lumin
2023 saw Diana create their first manga series, "MIKU's NY Broadway Diary", providing the story for the series, while artist Nobile provided the art. The series was first released the "Radio Chūgakusei no Kiso Eigo Level 1" educational book series in March, published by NHK Shuppan. The last chapter was released in February 2024.
On April 15, they released their second digital single "Genshindou", providing the theme song for the first ("The Shogunate") and fourth episodes ("Visiting Neo Inazuma") of the MiHoYo commissioned Genshin Impact alternate universe anime series, "Progenitor". Remixes of the song would also be featured as the opening and ending themes for episode 2 ("Albedo"). Furthermore, Diana voiced the character Klee for the series. As Klee, they contributed the character song "Klee's Lullaby" for the original soundtrack of the series.
On July 28, Diana released their third digital single "Heiwa Sanka", the theme song for the Yostar commissioned Arknights anime short film "Legend of Chongyue". Diana also contributed to the short film as a casting and voice director.
On October 31, Diana performed the theme song "Ruby Red Shoes" for AstralShift's acclaimed visual novel "Little Goody Two Shoes". They also voiced Elise, the protagonist of the game, and contributed the character song "Ruby Mirage Slippers" as said character for the original soundtrack of the game.
In December, they performed as a guest performer in the Yokohama leg of Flow's domestic tour, "FLOW THE CARNIVAL 2023: NARUTO Shibari". The concert was recorded and broadcast on Space Shower TV as a TV special on February 7, 2024.[31]
On February 11, Diana's VTuber character Lumin Tsukiboshi debuted through her first livestream. Originally introduced on a character sheet on September 20, 2023. The character maintains in her livestreams that Lumin and Diana are to be seen as two different entities, with "Diana Garnet" being her family-friendly real life identity with commitments to their clients, while "Lumin" would be able to interact with fans more and cover songs that wouldn't necessarily align with Diana Garnet's public image. Whenever Lumin alludes to her real life, she would refer to her persona "Diana Garnet" as "the voice inside".
Diana also provided vocals for the character song "No Name (English ver.)" of ninja Asahi, a character of the Bank of Innovation smartphone game "MementoMori".
In July, Diana performed the theme song "Set Sail" for the summer event "Beauty Full Shot" of the Shift Up smart phone game "Goddess of Victory: Nikke".
Later that month, production company Qubic Pictures teased the singer's live performance of a song at their panel discussing their 2025 Netflix anime series adaptation of the novel Leviathan by Scott Westerfeld at Otakon. It was later confirmed that Diana would be contributing a theme song for the upcoming series, the song they had performed at the panel, penned by Joe Hisaishi and arranged by Nobuko Toda and Kazuma Jinnouchi.
In October, Diana performed the character song "Lamb's Requiem" and co-wrote four different character songs for the Inti Creates game "Card-en-Ciel".[32]
They also provided vocals for the theme of the video game "The 257th Element" in August and performed the theme for the video game "Starlight Re:Volver" in December.
In December, they performed the theme "Michibiki no Hoshi" for the fifth episode ("Invasion") of the MiHoYo commissioned Genshin Impact alternate universe anime series, "Progenitor".
2025–present
Diana performed the theme "In Another Story" for the MiHoYo commissioned Honkai: Star Rail alternate universe anime short film, "Millennium Idol: In Another Life".
1. Sobakasu (そばかす) 2. My Revolution 3. Secret base (Kimi ga kureta mono) (secret base 〜君がくれたもの〜) 4. Akai Sweet Pea (赤いスイートピー) 5. Mikazuki (三日月) 6. Mata Kimi ni Koi shiteru (また君に恋してる) 7. Suki ni natte, yokatta (好きになって、よかった) 8. Chiisa na Koi no uta (小さな恋のうた) 9. Haru (Spring) (春〜spring〜) 10. Yuki no Hana (雪の華) 11. DEPARTURES 12. Ito (糸) 13. Arigatō (ありがとう) 14. Zankoku na Tenshi no These (Bonus Track) (残酷な天使のテーゼ 〜Bonus Track〜)
