Yes, in Japan that’s exactly what you should do. And they would go get it.

Definitely a legal system geared towards not letting a single bad guy go free at the expense of capturing the innocent --

And furthermore, Japan is a country built on saving face, couldn't the officer assume best intentions or simply a thief trying to come clean and let me slide without giving me the danged third degree? I was even wearing a bowtie no joke!

Yes, it's true that's what one ought to do, but really, is it? I mean this from a humanist level, is it really beholden to us as a society to need the intervention of the police state for something as peer-to-peer as returning a lost bicycle? Who am I to judge I'm just a stranger in a strange land.

Back home in Toronto, we have this silly habit of picking people's lost clothing items and putting them up on fences and signposts in case they come back to retrieve them. Under these circumstances here it's safer to walk on by -- same goes with the bike in the generalized sense the burden of returning the bike gets far greater due to the simple fact that most people simply won't bother, hence the need for a gaijin hero to step in and set things to rights

It's not only Japan. For better or worse, just walking by, leaving things as they are and calling the police is a better way to go in most of Europe, too. Usually it's for the better.

Exactly. I've done it before (for fly tipping, auto parts, discarded home appliances). They will take care of it, eventually. Or someone else will grab the stuff. Either way, not really your problem. If you get the bike, just repaint it and keep it I guess.

They will fix it. Just because your system is broken doesn’t mean everyone elses is.