The other day I met YOSHIKI. I was at a showing of We Are X in Oslo, Norway. Norway doesn't have a huge VK scene so I was happy he had come. It turned out to be his first time in Norway.
I asked him "Can western bands be visual kei?" - He laughed and replied "Of course!"
So I followed up with "If a western band is to be visual kei, is there something they must adhere to, in terms of style or aesthetic?"
He explained VK is more of a mindset, born out of them feeling like they didn't really fit in anywhere. As he said, they played "super heavy" and "super soft" music. He also told me about a festival he hosted recently where the bands were everything from metal to pop, and there was even a band that didn't play music (that got some laughs around the room). He summed everything up by saying it really isn't a genre, but more of a mindset allowing yourself to be as creative as you want. And it also generally has makeup.
I am summing these things up from memory.
So here's my take on VK:
1. You must be influenced by Japan/Japanese music (because after all, it originates from Japan).
2. Make creative use of makeup/visuals.
3. Be somewhat diverse in terms of style.
4. Be doing your own thing confidently (basically: be true to yourself, because people and fans can see through you being a cookie-cutter).
So basically, no you don't have to have a lolita in the band. One member doesn't have to wear a surgical facemask at all times. You don't have to have death-metal growls in your music. Some music fans within genres and subcultures get really elitist and that gets irritating, especially when people say that VK is only Japanese (so is glam-metal only truly American? Can you not make Brazilian samba music if you aren't from Brazil?). VK is unique in that it is vague but also has a meaning. A band alone isn't just "visual kei" but "visual kei rock" would be a better indicator. I think in that sense, the addition of the term "visual kei" before "rock" to me would indicate the above traits I listed, like being influenced by Japan, be somewhat "different" in terms of makeup/visuals and potentially have a diverse musical style.
I had a blast meeting YOSHIKI. He's a funny and nice guy, and it was an honor having him in Norway.