A Russian friend living in Japan noted that, at least as of a decade ago, a decent number of government services (for citizens) allowed something like 6 characters max for the entire name. This is because Japanese names are normally written compactly in Kanji, but it becomes a problem when your name is 15 Katakana or 25 Latin characters long.

"Константин Константинович Константинопольский" is a somewhat popular example of what one's design (graphical, computer system, whatever) should realistically allow for.

When I moved to Japan in 1983, not much was computerized and I was able to use my preferred short version of my name--eight letters or five katakana, surname last in both cases--for nearly everything. But over the years more and more places started requiring that names be input into labeled fields, which would reverse the given-name surname order. And many places started to insist on the same name as on my passport--nineteen letters, eleven or twelve katakana, depending on how I wrote it. Many input forms don't allow so many characters, none that I have encountered distinguish first from middle names, and there's usually no way to link that long name to the short name that I have been using for work and in daily life for more than forty years. It's a constant annoyance, not just for me but for other people.

This also usually applies to bank accounts, they have a character limit of around 16 characters for the whole name in most banks.

Of course it's not explicited in most places as 16 chars for a standard Japanese name is an exception, and some applications will silently cut when sending to their backend.

It's as fun as you can imagine it to be.

Even something as simple as buying a movie ticket can require submitting a name using only Japanese characters.