Genres: Hardcore Punk (early), Heavy Metal, Hard Rock (later)
Years active: 1983-1988, 1999, 2006, 2010~

Cult band from the 80s, Gastunk is known for their mixture of hardcore punk/metal during their early years and Baki's distinct vocals.
Many famous vocalists in the rock and metal scene cites Baki as influence, such as MORRIE (DEAD END), HYDE (L'arc en Ciel) and Kiyoharu (Kuroyume).

Held a one-off reunion in 1999 as a tribute to the late X JAPAN guitarist Hide , who was a fan of Gastunk.

Baki left the band in 2022, a year after releasing their comeback album.