KOIAI BIOGRAPHY

Japanese Hard Rock Driven by Twin Guitars:
KOIAI and a New Line-up's Fresh Start

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.

The KOIAI LIVE TOUR 2026 "Starting Over" opened five days after the EP, on July 20 at Music Club JANUS in Osaka, and ran through five cities: Osaka, Sendai, Tokyo, Fukuoka and Nagoya. Its third date, Tokyo on July 31, doubled as Day 1 of Heavy Kawaii Fes 2026 at Meijiza, and the band played all three days of the festival, July 31 to August 2. The change of vocalist is written directly into the title: this is a fresh start.

On August 25, 2026 the band appeared as VΛND from KOIAI, without vocalist Mirei Sakurada, alongside METALVERSE at VERSE BY VERSE #1 at Zepp Haneda, and on October 3 it played ZEPHYREN x SHIBUYA THE GAME presents In The Family FEST 2026, a circuit festival across seven Shibuya venues. Appearances at BUZZ RHYTHM LIVE 2026 DAY1 at Yokohama Arena on November 6, on the same day as METALVERSE, and at MIXED HELL 2026 SECOND at CLUB CITTA' in Kawasaki on November 28 were also announced. So was KOIAI 1st Anniversary since the REBOOT, a headline show at Theater G Rosso in Tokyo on November 21, 2026, marking a year since REBOOT, the November 22, 2025 headline show at Nihonbashi Mitsui Hall where the current five-piece first played together.

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

Until October 12, 2026, she was also 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. 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.