My answer is late, but if you insist going there - just don't. First, this place is runned by japanese mafia. Going there and just mentoining his name may end up dead. And here I will quote an article I read - Going to a place when someone died from a violent death isn't a good idea from any aspect. First, something bad happened there, bad spirits or whatever you call it, bad presence. If you want to honor his memory go somewhere he would go, or he was. Find interviews and photos with his favourite places and go there, or at similar place. Do something that reminds you of him, draw/paint him, write a song, make a cover song, light a candle... Visiting a place he died? What for? He is not there anymore. Better visit his grave, but he is not there either, you will find just a piece of stone with his name on it. I just don't think this is the way, but after all this is all your decision.
Second and most important thing is your security. Nobody can asure you that you will come back from that trip. He was a world famous rock star and six years after that they can't prove his death wasn't a suicide. Yes, I believe in this, if you don't, fine. Going there, digging abut what happened - you must have strong protection doing that, police or government. That's what I think. Excuse me for interrupting.