Although Hideto "hide" Matsumoto is deceased, the band still considers him a member and introduces him at every concert, with the group going as far as to play audio/video clips of his voice/guitar for some songs.

X Japan first new song since "The Last Song" in 1998 was "I.V.", the main theme song of the american film "Saw IV", released in 2007.

X Japan can also be seen in the movie Tokyo Pop [1988] as the band mates of Diamond Yukai.

The name X was originally a temporary name ("X" as in "we are still thinking of a better name"). "X" became "X Japan" after the band tried to enter the American music industry and saw that the name "X" was already taken.

There is also an X Japan video game called "X-Japan Virtual Shock 001" for Sega Saturn.