What you have written has been refuted over 200 years ago, hence the RKBA. FYI, You are a little late to the party.
I challenge you or anyone else to walk into a gun dealers place of business and legally walk out with a gun without a NCIS Check and completing a form 4473. Sans an Eric Holder/DOJ Gun Give Away it is not going to happen. The whole NO BACKGROUND check is another faux liberal straw man used in a sad propaganda attempt to disarm America's Citizenry.
You keep bringing up Japan? Your argument is equal to that of saying because people are killed due to medical malpractice (much more than gun related deaths) that the absence of doctors would eliminate mal practice related deaths. I know I won't stop seeing my physician despite the number of deaths that are related to medical mal practice.. will you?
If Japan is your "utopia" why have you not made your way to The Land of The Rising Sun? I will tell you why, because no place on earth is better than The USA that is why. You and I both know this.
Finally, you are welcome to cling to your faux liberal notions and remain on fantasy island. Men with GUNS give you this freedom.
You are welcome for that.