Immortal Man

Hirasawa wrote the song to test out the skills of Toshihiro Ooe, his chief stage lighting technician at the time; during the song's writing it was referred to as Ōe Taisaku (オオエ対策).

Versions
Hirasawa wrote sheet music for multiple sessions across various albums to guide second engineers. Due to the heavy amount of sampling, he struggled to chart this song. He drew "snakes, hammers, gears and radio waves" over staves, which the engineer found easy to understand.
 * Virtual Rabbit, 1991
 * Susumu Hirasawa - Composition, Lyrics, Production, Vocals, Guitar, Synthesizer, AMIGA, Computer Programming
 * Yuichi Kenjo - Production
 * Masanori Chinzei - Engineering, Remastering (HALDYN DOME version)

Has a percussion led intro, with a slight variation of the woodwind melody on top. It replaces the song's opening bar, being slightly longer than it. On the second repeat of the chorus, Hirasawa plays the cymbals through Tubular Hertz; the following acoustic strumming bit is longer, with a rising synth noise and some Photon playing.
 * HIRASAWA error ENGINE - Hirasawa Three Acts in Three Hours: Upper, 1994
 * Susumu Hirasawa - Vocals, Guitar, Synthesizer, AMIGA, Computer Programming, Tubular Hertz
 * Motohiro Yamada - Engineering
 * Atsushi Hashimoto & Hirohisa Yamamoto - Public Address

Has a flute led intro, with the beat entering on the second bar, neither of them varying from the studio version. Certain sounds are updated from the original (among them the cymbals) and played through the Graviton. The rising synth noise appears on the same place as on the error ENGINE version.
 * PHONON 2550 LIVE/PHONON 2550 VISION, 2007
 * Susumu Hirasawa - Composition, Lyrics, Production, Vocals, Guitar, Synthesizer, Computer Programming, Graviton
 * Masanori Chinzei - Engineering, mastering

Connections

 * "Amor Buffer" is another sample collage akin to this song.
 * "Zoddo II" has a horn arrangement similar to this song's.

Trivia

 * The song appears at a singles chart, ranked 87 and performed by Kaoru Hirai (平井薫), in a scene of the film Perfect Blue.