THESTRAIGHTLINE was launched in the summer of 2012.

A three-piece band from Fukuoka consisting of Ryoichiro Matsuo (vo. gt.), Shio Okawa (ba. cho.), and Nariaki Kawaguchi (dr. cho.).

January 2013: Released "unsuspecting", a sound source for free distribution.
May 2014 1st MINI ALBUM "ALTERNATIVE SPACE" released
September 2014: Limited distribution single "genial warmth" released
October 2014: Inactive due to departure of first bassist Takahiro Takashima.
June 2017 Activities resume with new bassist Takashi Nakajima joining the band.
February 2018 Limited distribution single "Identity" released
February 2019 Limited distribution single "GREENLIGHT" released
January 2020 Limited distribution single "Zimbabwe the Melapsody" released
April 2020 Limited distribution single "Circle of Rainbow" released
January 2021: Limited distribution single "Set You Free" released
July 2022 Bassist Shio Okawa officially joins the band after providing support at a live distribution event in June.

The band's Japanese name, "Ichijin Line", means "a straight line". The band is active in Fukuoka under the motto of "enjoying sound in a straight line," with no one specializing in any particular field.