KOIAI
Biography and full discography of KOIAI, with a page for every album, on METAL BOOST.
Biography
Japanese Hard Rock Driven by Twin Guitars:
KOIAI and a New Line-up's Fresh Start
Profile
| Formed | December 2022, Japan |
|---|---|
| Members | Mirei Sakurada (Vocal) / Li-sa-X (Guitar) / Hazuki (Guitar / NEMOPHILA) / Yunika Impact (Bass) / Kanade Sato (Drums) |
| Former Members | Kotono (Vocal, 2022–2025) |
| Origin | Japan |
| Styles | Hard Rock, Progressive Metal |
| Labels | Ferment Label (Nippon TV Music) / Interstellar Production (until 2024) |
1. A Band That Reached an Overseas Stage Before Its First Record
KOIAI is a Japanese band formed in December 2022, built around the two guitarists Li-sa-X and Hazuki. Just two months after forming — and before it had released a single official recording — the group was invited to the Oddball Festival in India in February 2023, sharing a bill with The Aristocrats and Bloodywood. The usual order was reversed: the offers from abroad came before the records.
Descriptions of the music vary. Speaking about the early "Take It or leave It," the band said the song had come out not as something metal-leaning but as laid-back, authentic hard rock; overseas music media, meanwhile, have introduced KOIAI as writing genre-defying material somewhere between metal and jazz. The stated concept is "pop, rock and danceable," and the consistent aim is to make technical playing and immediately singable songs work at the same time. What follows covers the band's formation, its four EPs, and the new line-up that emerged after a change of vocalist.
2. From Li-sa-X BAND to KOIAI (2022)
KOIAI's origins lie in Li-sa-X BAND. Li-sa-X is a guitarist who debuted at the age of twelve, and Hazuki supported her as a guitarist for six years. Kotono, meanwhile, had come through the break-up of her former band IRONBUNNY. When both groups wound down at around the same time, the three found themselves free to work together.
The immediate trigger was a Polyphia cover the three of them played together. In December 2022 that meeting became KOIAI. Hazuki was by then already active as a guitarist in NEMOPHILA, so the band began as a project its members would run alongside other commitments.
3. Two EPs and a Settled Four-Piece (2023)
On May 1, 2023, KOIAI self-released its first EP, Deep Indigo, containing "Make You Regret," "Future of Those Days," "Your Socks," "No More Lies" and "Take It or Leave It." A short version of "Take It or leave It" had appeared in February, ahead of the EP, and a music video for "Make You Regret" followed on May 6.
The second EP, Deep Love, came on October 6 the same year through Interstellar Production (catalog number ISPR-0002), with "Inside," "One Way or Another," "Straight To My Heart," "A New Picture" and "My Breath" — barely five months after the debut. Then, in December 2023, at a show celebrating the band's first anniversary, drummer Kanade Sato joined as the fourth official member, settling KOIAI as a four-piece.
4. Come see me and the First Overseas Tour (2024–2025)
The third EP, Come see me, was released on CD on November 20, 2024 (Interstellar Production, ISPR-0004), with a digital edition on December 10. The title track's video had appeared three months earlier, on August 15. At home the band sold out a 1,000-capacity headline show, proving real drawing power two years after forming.
In March 2025, however, it was announced that Kotono — the band's vocalist since its formation — would step away to seek treatment for her ears and throat. KOIAI nonetheless made its first trip to Europe at the end of June: the Japan Tours Festival in Tours, France on June 29, Helios 37 in Cologne, Germany on July 2, and Anime Messe in Potsdam on July 5 and 6. Those shows were played around Li-sa-X and Hazuki, with nene on vocals and Wakazaemon (ex-East Of Eden) on bass as support.
5. The New Line-up and Starting Over (2025–2026)
In November 2025, Mirei Sakurada joined as the new vocalist and KOIAI restarted. In March 2026, bassist Yunika Impact became an official member, settling the line-up as a five-piece: Mirei Sakurada (vocals), Li-sa-X (guitar), Hazuki (guitar), Yunika Impact (bass) and Kanade Sato (drums) — the first full line-up in the band's history that needed no support players.
On May 29, 2026, KOIAI was announced as the first artist signed to Ferment Label, a new 360-degree artist business launched by Nippon TV and Nippon TV Music. The fourth EP, Starting Over — the first record by the new line-up — followed on July 15 (FRMT-009). Its title track had been released digitally on June 3 and was also used as the August 2026 ending theme for Nippon TV's DayDay.
After the release the band played Heavy Kawaii Fes 2026 between July 31 and August 2, then opened the KOIAI LIVE TOUR 2026 "Starting Over" in Fukuoka on August 10. The change of vocalist is written directly into the title: this is a fresh start.
6. Detailed Member Profiles
Mirei Sakurada — Vocal
The vocalist who joined KOIAI in November 2025. She fronts the band's restart after Kotono's departure, with the fourth EP Starting Over of July 2026 her first record with the group.
Li-sa-X — Guitar
A guitarist who debuted at the age of twelve and stands at the center of KOIAI, which grew directly out of her earlier Li-sa-X BAND. Her twin-guitar partnership with Hazuki is the band's musical axis.
Hazuki — Guitar
Also active as a guitarist in NEMOPHILA. She supported Li-sa-X as a guitarist for six years after the latter's debut at twelve, and that relationship became the foundation KOIAI was built on.
Yunika Impact — Bass
The bassist who became an official member in March 2026. Her arrival made KOIAI a five-piece and completed a line-up that no longer needs support players.
Kanade Sato — Drums
The drummer who joined as the fourth official member in December 2023, at a show marking the band's first anniversary. She is known for playing with considerable power despite a slight build.
Kotono — Vocal (2022–2025)
KOIAI's vocalist from the band's formation. She joined after the break-up of IRONBUNNY and sang on three EPs — Deep Indigo, Deep Love and Come see me. Her departure, to seek treatment for her ears and throat, was announced in March 2025.
7. Discography
| Year | Title | Format |
|---|---|---|
| 2023 | Deep Indigo | 1st EP (May 1, self-released) |
| 2023 | Deep Love | 2nd EP (October 6) |
| 2024 | Come see me | 3rd EP (November 20) |
| 2026 | Starting Over | 4th EP (July 15) |
8. Summary
KOIAI is a Japanese band formed in December 2022 around the guitarists Li-sa-X and Hazuki. It began in unusual fashion, invited to a festival abroad before it had released anything, and across four EPs has grown into a group that sells out 1,000-capacity headline shows and tours Europe. A change of vocalist did not stop it: with Mirei Sakurada and Yunika Impact aboard, the five-piece now stands as the first artist on Nippon TV Music's new label. As the title Starting Over says, the band's story is at its second beginning.
Trivia
KOIAI exists because of a cover video. Li-sa-X had known Polyphia for years — she had even opened for them on a Japanese tour — and the three of them, Kotono, Hazuki and Li-sa-X, liked the sweetness of the lyrics to "ABC" enough to try covering it as an experiment. It was the middle of the pandemic and they could not get into a room together, so each filmed her part separately and the footage was assembled remotely. The band treats what came out of it as the record of where everything began: making it is what settled the decision to become a band at all.
The first big stage KOIAI stood on was not in Japan. In February 2023, with no official recording to their name, they were invited to the Oddball Festival in India and played three cities on a bill that included The Aristocrats and Bloodywood. The self-released debut EP Deep Indigo did not arrive until three months later, on May 1, and even then only by mail order through the band's own web shop. The offers from abroad came before the records did.
For Mirei Sakurada the call from KOIAI was the last chance. She had done nothing but sing since she was small and had been turned down at audition after audition; she was working out what to do next when the band got in touch. She decided she was going to be KOIAI's vocalist, and that was that. People tell her she does not look like someone who gets nervous. The night before her first show with the band, she cried.
Starting Over began with Li-sa-X unable to write. The shock of losing a member was still there, no clear picture of what the band now was had formed, and she describes the stretch plainly as a slump. So the first two songs, "Starting Over" and "Reboot the Abyss," were written by the producer, with Li-sa-X, Hazuki and Kanade Sato putting their own stamp on them through the arrangements instead. Yunika Impact joined the writing from the third track, "Once in a lifetime," and the closing pair, "Hoax" and "Meant to be," are Li-sa-X's own — finished, by her account, right up against the deadline.
The three of them met through radio. Kotono's former band IRONBUNNY hosted a programme, and both Li-sa-X and NEMOPHILA — the band Hazuki plays guitar in — had appeared on it, which is how they first came to know one another. Then Li-sa-X BAND lost its vocalist at almost exactly the moment IRONBUNNY broke up. With both footings gone at once, the conversation turned to trying something together, and KOIAI followed.
Two sleeping incidents came out of the India trip. Hazuki was rooming with Kotono, who at one point sat bolt upright in bed, folded to a perfect right angle, then dropped back down and carried on sleeping — with no memory of any of it afterwards. The other involved drummer Kanade Sato, who fell asleep with the room locked from the inside, leaving her room-mate Li-sa-X shut out. The whole band had a go at waking her. None of it worked.
Hazuki's first thought on meeting Li-sa-X was that this was what a prodigy actually looked like. She has been alongside her ever since — from Li-sa-X's first solo show, through Li-sa-X BAND, and into KOIAI. Hazuki calls her something like a younger sister, though in her own column she admits what she feels is sometimes closer to a mother's protectiveness. Two lead guitarists in one band, and by both their accounts, not a trace of rivalry in it.
Mirei Sakurada came in through an audition. The band still had shows on the books after their previous vocalist left, so something had to be settled quickly. Other singers were put forward, Hazuki says, but the moment they met Sakurada the decision was unanimous. Settling a vocalist settles a band's direction, and by her account the months that followed — the writing included — went smoothly from there.
News
Eric Martin (MR. BIG) Releases Third Trailer For His First Documentary Film 'KIZUNA'
The film traces the 40 years since his 1985 solo debut and his ties with Japan, and opens across Japan from December 4. Saimon Kawagishi directs, Katsuya Kobayashi narrates, and Takahiro Matsumoto (B'z), Sou Takei, Li-sa-X (KOIAI), Kanade Sato (KOIAI) and Wakazaemon appear.
Play MVKOIAI To Release Live Blu-ray Of Their Meijiza Show On October 28, With A Release Event At Yokohama Bay Hall On October 25
The disc captures all 21 songs from KOIAI's set at 'KOIAI LIVE TOUR 2026 Starting Over in TOKYO / HEAVY KAWAII FES 2026', held at Tokyo's Meijiza on July 31. The limited first edition (9,500 yen incl. tax / FRMT-010) comes with a 48-page B5 photo book, and the standard edition is 7,500 yen incl. tax / FRMT-011. Ahead of the release, a 'Talk & Live' release event takes place at Yokohama Bay Hall on October 25, featuring a live set, a talk segment hosted by Ken Ayukai, and a signing session for those who buy the Blu-ray at the venue.
Current Members
Current lineup verified from the official artist source on 2026-08-10. Official profile
Albums
KOIAI's fourth EP and the first release by the settled five-piece line-up with vocalist Mirei Sakurada; the title track became the August 2026 ending theme for Nippon TV's DayDay.
The last EP recorded with founding vocalist Kotono — five songs led by the title track, whose video came out three months ahead of the release and carried the band to its first European shows.
A second EP arriving barely five months after the first, its five songs — from “Inside” to “My Breath” — each issued in turn as official audio.
The self-released debut EP — the first five songs put out by a band that had already been invited to a festival in India before it had any recordings at all.