Gun laws are a big one...but it's not just about gun laws or lack there of. The 2nd Amendment is only a symptom of the greater issue--Rights, Liberty, and Freedom. If I have no means to protect myself, my family, and my property, and I have to rely on the government to protect me, then I can easily lose everything I have (my life, my family, my property) because the government can't be everywhere, they don't have an obligation to protect me or you (at least here in the US in regards to the police/LE), and they can also turn on you if they see fit...internment camps for Japanese Americans quickly comes to mind.
But it's not just about the 2nd Amendment, it's also about being able to live the way I see fit as long as it doesn't take away that same ability from somebody else. In Germany, it's illegal to homeschool your children, with very rare exceptions. I call this a barrier to liberty. In the UK, they don't have the same/equivalent '5th Amendment' type Rights that we do here in the US, and what they do have isn't nearly as protective.
Taxes also have to do with freedom and liberty--the more you take from what someone has earned, the less opportunity they have to do with it as they chose (ie liberty), especially if that money is taken only to be redistributed to somebody else.
(Here's a study that George Mason University does every so often on the 'freedoms in the 50 States' and details what States are best in terms of respecting Rights and Liberties. It's State comparison vs international, but it details what I'm describing pretty well )
I could go on and on, but I think you guys get the idea. So going back to Japan--no 2nd Amendment type Rights, their current constitution continually discusses 'public welfare' and states that human rights are subject to restriction when it interferes with the public welfare, it states that people are obligated to work, and have very strict rules on the education of children.
Articles 25 states: "All people shall have the right to maintain the minimum standards of wholesome and cultured living. In all spheres of life, the State shall use its endeavors for the promotion and extension of social welfare and security, and of public health." I'll at least give it to the Japanese...they come out and directly say they are for entitlements in their constitution instead of how we do it here in the US...but either way, they require more taxes to fulfill this constitutional right, which leaves less money to the people to make their own decisions. Oh, and Article 26 states, "All people shall have the right to receive an equal education correspondent to their ability, as provided by law."...sounds to me the law has a lot to say in how people receive their education...not so much in our Constitution.
Let's see, what else...the country does not recognize gay marriage, their marijuana laws/sentences are much more strict than in the US (and hell, it's legal here in some places), they also have stricter environmental laws, have higher personal taxes (especially when compared to States with low tax rates)...ok, I'll stop there.
BL: Chida, I could care less where you live man. If you want to live in Japan, Australia, Nigeria, wherever...I'm all about people making their own personal decisions. But if you say something like 'the weather in Antarctica is better than in the lower 48 States', then I'm going to call you out and raise the bullshit flag. It's a tough argument to make that 'Japan is the same in the freedom dept'--so either clarify, or be called out. And like I said in an earlier post, I'm not a 'America--fvck yeah!' kind of a guy as I believe our country is going down the shitter. So I'm not picking on Japan or anywhere else, rather I'm just calling it like I see it.
ETA: Forgot to answer your question, no, I have not been to Japan, though hopefully I'll get the opportunity some time to visit. Most of my time overseas has been spent in Europe and in our other glorious locations that we get sent to. Fortunately Japan's constitution was available via google as well as other articles describing things in their country. By all means, let me know if I missed something--if there's more Liberty in Japan than in the US, I may just have to join you there some day.