The guns/suicide link comes from studies from Harvard (http://www.hsph.harvard.edu/news/magazine/guns-and-suicide/), The University of Southern California (as linked before) and the New England Journal of Medicine (http://www.nejm.org/doi/full/10.1056/NEJMp0805923). So you might want to reconsider your views on it. The Japan thing is a separate country with a very different culture, so a red herring. The above suicide studies are all within the US, so culture factors are already controlled for.
Given the wide variance of crime rates within the US, I would suggest that the states with higher murder rates implemented tougher gun laws as a response to high murder rates. The leakage of guns from adjacent states with lax laws would hamper those law's effectiveness. In order for it to work, the laws would have to be country wide, but I don't see that happening.
I'm quite happy for you to live your life as you wish, providing you don't go about gratuitously harming others. I just don't want a cultural meme, which has shown itself to be problematic, to say the least, to be exported to my country.