2001: One Life, One Death Cut Up live album and video released on March 28.

On July 29, Buck-Tick played at the "Soyo Rock Festival 2001" in Seoul. There was bad weather and it rained during the festival and Buck-Tick's performance. At the time, Buck-Tick did an interview on Korean television in which they mention that the last time they went to Korea, they were unable to play live. They were referring to the fan meet and greet 1 year prior.

Atsushi and Hisashi became involved in the side project Schwein, with Raymond Watts (Pig) and Sascha Konietzko (KMFDM). Their album Schweinstein was released on May 9. They toured in August but without Sascha. The live band comprised of Jules Hodgson (guitar), Bryan Black (keyboard), Andrew Selway (drums), and Arianne Schreiber (backing vocals). The tour was entitled "Schwein Fest Tour Japan 2001" and lasted for 8 dates. They would play some Schaft, Pig, and Buck-Tick songs. The Son of Schweinstein remix album was released on September 5. No singles were released but the remix album did feature a bonus video for "You're My Disease" which was apparently filmed in the New York City area.
"21st Cherry Boy", the first single from the new album was released on November 21. The new album would be released on the following year.

On December 29, Buck-Tick played their first "The Day In Question" gig at the Nippon Budokan in Tokyo. How once the band liked to label special shows as "Buck-Tick Genshou", in the 2000s they like to label special end of the year shows as "The Day In Question".