The band consists of Ba/Vo GEN, Gt HIROKAZ, Gt/Cho RYU-TA and Dr/Cho KOUHEI.
04LS made their major debut from Nippon Columbia with the 1st full album 'CAVU' in 2015.
In April 2016, the band's outdoor festival "YONFES" was held for the first time in their hometown Aichi-prefecture.
The band held their first concert in Nippon Budokan in February 2017.
In 2018 the band celebrated the 10th anniversary and conducted the Tokyo/Nagoya/Osaka Arena Tour.
They held a solo concert "YON EXPO" in Saitama Super Arena for the first time in their band's history.
From January 2020, they have embarked a tour called "MISTERY TOUR 2020", a joint concert with the secret guest bands which are only unveiled at the day of the event.
Their overwhelmingly aggressive live act always thrills the audience, especially because of 04LS's beautiful melodies and with Gen's high-pitched vocals.