Iroha began somewhere in 2000, the band consisting of Maeno on vocals, Etta on guitar, Kazuki on bass and Shintarou on drums. Neither of them had been playing in a band before, although Kazuki had been a roadie of MUCC.
A line-up change was made in the beginning of their career, Maeno left the band and shortly after he was replaced by Shinnosuke, who had been a member of the band lu;fiene before.
From the start until 2003, they did what every beginning band did: performing on a lot of events and releasing several demo-tapes. They seemed quite successful though, seeing as the demo-tapes sold out and they had to release a second press. They also had their first one-man concert in this period and appeared on an omnibus album.
In 2003, it was finally time for a first single for Iroha. However, they didn't just release one single, but they released two singles --Orange Sugoroku and Ura Keshiki-- at the same time.
The band was very active in 2004; they performed a lot, released three singles and the mini-album, Makairo Yumegatari. The fans had to wait until 2005 before they released their first full album, which was released in March 2005, called Asaki Yumemiji Yoimosezu. However, almost all these songs had been released before and it was more a compilation album.
About a month later, Iroha disbanded after a concert on April 24th at the Takadanobaba area. It turned silent around the members and it seemed all of them had left the music business, but slowly they resurfaced again. In May 2006 Etta and Kazuki started a new band called Gechena, but after its disbandment in October 2007, it's been silent around the two. After a long period of inactivity, Shinnosuke became part of the session band MM FANTASY, that later turned into the band Aibell. Drummer Shintaro is currently a member of Metronome.