The band consisted of Toshi (vocals), YOSHIKI(drums, piano, composer, lyricist), hide (guitar), Pata (guitar), and Heath (bass), and Taiji (bassist) until 1997 when they disbanded.

Once Yoshiki and Toshi recruited bassist Taiji and guitarists hide and Pata, the band began moving on the indie circuit. They garnished abundant support and fans across Japan with their outrageous dress style.

They used long, dyed hair and leather, along with makeup to make themselves shocking to the people who went to see them. This look, and their musical styling of fast, heaving, hard driving speed metal, mixed with softer and more heartfelt ballads, was the defining origin of today's visual kei bands.

However, in 1996, after the release of their fifth and final album, DAHLIA, Toshi announced that he was departing from the band, for his own reasons - rumored to do with his wife disliking the band, ie: his time commitment and also with their performance of mostly sad, downbeat songs. Rather than go on without Toshi, the following year X JAPAN announced it was breaking up. At the end of the year, they had their final concert. X Japan split up in 1997.

Four months later, May 2, 1998, Hideto "Hide" Matsumoto, X Japan's lead guitarist, was found dead, hanged with a towel tied to a doorknob in his Tokyo Apartment. While authorities deem the guitarist's death a suicide, several of Hide's friends and colleagues stated that they believed in an accident, this was supported by the fact that there was no suicide note.

However, a new wind has begun to blow for X JAPAN, as Toshi has stated his desire for a reunion for the 25th anniversary of the band's founding.

Currently it was anounced Yoshiki is talking to Pata and Heath for the reunion. A tour and new release (Without You) has already been scheduled for 2007, no dates are known yet. Also 10 guitarists will be playing the guitar parts of hide.

Update: (text from wikipedia)

In March 2007, Toshi announced on his website that he and Yoshiki had recently resumed working together, stating that a "new project" would commence soon. An X Japan reunion was officially confirmed on June 4, 2007, with Yoshiki announcing a tour, as well as a new single (a re-recording of the song "Without You", originally from Yoshiki's 2005 solo album Eternal Melody II) to be underway and that he was in talks with Heath and Pata, regarding their participation. About ten undisclosed guitarists were to fill in for the late Hide during concerts.

The band held its first live performance on October 22, 2007, on the rooftop of the shopping center Aqua City in Odaiba, Tokyo, during which a music video for the newly recorded song "I.V." was filmed. "I.V." also appears on the soundtrack of the movie Saw 4, it is written by Yoshiki and recorded with all living X Japan members of the pre-breakup lineup. Previously unreleased guitar tracks by Hide were used for the lead guitar part.

On January 20, 2008 three concert dates were announced, two to be held in the Tokyo Dome, on March 28 and March 30 respectively and a Hide tribute concert at the Tokyo Stadium on May 2, the tenth anniversary of the musician's death. Sugizo has been tentatively announced as a guitarist for these performances.[9] A third Tokyo Dome date, March 29, was later added to accommodate demand. Guitarists performing with X Japan during these three concerts were Wes Borland of Black Light Burns, Richard Fortus of Guns N' Roses and Sugizo, in addition to the use of old live footage of Hide. Fortus and fellow Guns N' Roses member Robin Finck had previously covered "Endless Rain" as a guitar duet during the Japanese shows of their band's 2007 tour. Borland later commented on his blog that he felt "honored to have been part of the experience".

On January 23, "I.V." was released through the iTunes Store and is also set to be included in an upcoming best of compilation, along with the previously announced "Without You".

When "I.V." was announced as a digital download, it became the top most preordered song worldwide.

On Dec 31st 2008 X held a Countdown gig At Alaska Blitz in Japan to celebrate the new year. it was arguably the return of X . Once again Sugizo is the special guitarist. Make many wonder if he will be the 6th man of the band. At the end of the countdown gig many new tour dates were announce including New York And Los Angeles.