Somewhere to put it down.
You buy a coffee at nine in the morning. At four in the afternoon the cup is still in your bag. Nothing has gone wrong, exactly — but it has been there all day, and you have been half-thinking about it all day.
This is not a mystery, it is a policy
Public bins were removed from Japanese stations and streets after 1995, and largely never returned. Cleanliness held anyway, because the habits around it changed instead: people carry their rubbish home, shops handle their own customers' waste, and drinks containers go back beside the vending machine they came from.
That system works beautifully if you live inside it. If you arrived on Tuesday with a suitcase and a coffee, nobody has explained any of it to you. You are not doing anything wrong. You are missing one piece of information, and it is surprisingly hard to find.
One promise
We will never present a guess as a fact. That sounds small. In practice it is the entire product, and it costs us most of our map: of 5,363 points on record in Japan, 619 have been confirmed on the ground, and we say so on the front page instead of burying it.
Every other decision follows from that one. Checked points outrank close ones. Unchecked points are visibly, deliberately quieter. Empty is an acceptable answer. And the number we are trying to grow is not how many pins we have — it is how many of them somebody has actually stood in front of.
Where it goes
Trash is the wedge, not the ambition. It is the thing a traveller needs at the exact moment they are least able to look it up. If we can be reliably right about that, the same approach — real records, honest confidence, one-tap verification — applies to every other small piece of infrastructure a visitor needs and cannot see: water, lockers, toilets.
But only in that order. Being vaguely useful about six things is worth less than being completely trustworthy about one.