Traffic accident: Was I charged or not?

About 7 years ago, I was in a minor traffic accident in Japan in which I lightly tapped the bumper of the car in front of me. We were in slow-moving (3/4 kph), bumper-to-bumper traffic, and I couldn't bring my car to a full stop quickly enough when the other driver slammed on his brakes. When we pulled over and inspected the cars, we saw absolutely no damage to either car, not even a scratch. This was later confirmed by the police and insurance appraisers. The other driver and his passengers said they hadn't suffered any injuries.

After the police arrived, we all went to the station to make statements, and then went our separate ways. At a later date, I had to go to the office of a city-appointed attorney (prosecutor?) and answer various questions about the accident. The other party did the same on another day. Over the next two months, there was a lot of back and forth through informal mediators. The other party changed their story and claimed they had suffered terrible injuries that would require extensive physical therapy, but the police investigated this and found it to be false.

One day my boss -- who was helping me handle the problem -- came to me and said the matter had been concluded. There were no apparent charges or fines, and no court summons. While I was relieved and very grateful, the conclusion was weirdly abrupt. I thought that I would have been fined, at the very least.

None of the typical legal procedures for traffic accidents in Japan seem to apply to my case. According to what I've read, I should have been fined a fee for a minor accident (if I admitted guilt), which I would then pay to conclude the matter without a criminal record. If I had refused to admit guilt, the case would have gone to a prosecutor, who would then determine the next step.

I willingly agreed I was at fault from the very beginning, so why wasn't I simply fined? Why did the case go to a prosecutor, and then drag out for months? Does that mean I was formally charged with a crime, but the prosecutor eventually decided to drop the charge? I'm asking now because I'll be moving out of Japan soon, and want to be able to truthfully answer any questions about past criminal charges should I decide to return someday.

A legal case may be either civil or criminal. What would have been criminal about your case, even if you were under investigation for a spell?

While the following isn't about Japan, it's a good start at understanding the civil/criminal distinction in the law:

"There are several ways in which an auto accident -- usually a civil incident -- can escalate and become a criminal offense. While the laws vary by jurisdiction, there are three commonly recognized types of auto accidents that can result in criminal charges."

http://www.lawyerlocator.com/auto-accidents/criminal-offense-auto-acci...

While I understand you may be trying to help, what I think may or may not have been criminal is moot because my opinion does not control a country's laws or judgements on cases. And U.S. law does not apply to Japanese law. I'm seeking insights based in fact and Japanese law, not on rhetoric and perception.

wow I never heard or experienced this.

I drive so long in Japan and had several minor accidents, some my fault some not my fault.

But so far I just got some minus points on my licence or a fine, which I pay and finished.

Your story seems really different, especially bumper to bumper.
for that you need to go to have so many talks....

it went far because people with selfish interest and insurance company .

just go to that office station get a copy of clearance of criminal case.

is not a big case it can happen to anybody.