X Japan superstar looks at what could have been

But could X Japan have been far bigger on the world stage? In a new documentary on the band, Gene Simmons of Kiss relates his awe at discovering X Japan and opines that, had the rockers been American or British, they may have been the world's biggest band.

"We Are X," which opens in US cinemas on Friday, explores the rise and turbulence of the band that found unprecedented glory in Japan's high-flying 1980s.

Led by Yoshiki, the physically frail but musically furious drummer, pianist and songwriter, X Japan took inspiration from the power of arena rock but with the glam flair of David Bowie and firm underpinnings in Western classical music.

"We Are X" -- directed by Stephen Kijak, who previously filmed the Rolling Stones -- follows X Japan as the band's reunited surviving members play New York's Madison Square Garden in 2014.

Yoshiki, in an interview with AFP, noted that the Tokyo Dome -- where X Japan performed its farewell concert in 1997 -- had three times the capacity of 18,200-seat Madison Square Garden.

"But when you're talking about making it in the whole world, Madison Square Garden is one of the goals," he said.

"We Are X," which premiered at the Sundance film festival, shows the band's awkward initial attempts at international success.

The rockers in 1992 hurriedly learned English and gave a news conference in New York to announce a US recording contract, yet X Japan's foreign fan base was to remain niche.

"It was almost like a mission back then," Yoshiki said of going global. "But we were not 100 percent sure we could do it, because the world was not ready."

Yoshiki, 50, believes X Japan's trajectory could have been different if the band had been born later.

"We now have the same opportunity to achieve as those who were born in America and England."

In the past 30 years, Japanese culture from sushi to Pokemon has swept the world and the internet has transformed the distribution of music, he said.

South Korean rapper Psy's "Gangnam Style" reigns as the most-viewed video ever on YouTube, with its equestrian-style dance winning an audience who barely understands a word.

"These days anything can happen because of the internet and everything," Yoshiki said.

"The world has kind of changed so any artist from Japan or anywhere -- China, anywhere in the world -- may be able to make it and became a worldwide known artist."

The documentary also shows the darkness lurking behind X Japan's fame.

Yoshiki, sickly from a young age with frequent bone fractures, is haunted by his father's suicide and takes out his aggression through music.

With X Japan, he would sometimes convulse in pain on stage, with audiences mistakenly thinking he was acting.

And just months after X Japan split up, lead guitarist Hideto Matsumoto, better known as "hide," was found dead from hanging, with fans throwing themselves on his funeral procession.

His death was ruled a suicide, although Yoshiki in the documentary contended that hide accidentally died from "neck-stretching" exercises.

"We Are X" also shows the reconciliation between Yoshiki and singer Toshi, whose decision to leave the group triggered the 1997 breakup.

Toshi explains in the documentary that he had been brainwashed by a cult that made him ashamed to perform and seized his money.

Yoshiki, who composed a work for piano and strings to mark Emperor Akihito's 10th anniversary on the throne in 1999, has stayed active in classical music and recently announced Carnegie Hall performances for 2017.