Most computers handle Japanese character input pretty well these days.
That is to say, both Windows (since Windows XP) and Mac OS/X (since I dunno when) come with an IME built in and a set of Japanese fonts.
It’s a lot better than the old days when you needed to install Win95/J, for sure.
Anyway, there are a bunch of symbol characters in the Japanese fonts, useful stuff like • and ★ that you can get by typing in てん and ほし (“dot” and “star”), respectively.
On the other hand, if you can’t be arsed to learn all the different shortcuts for getting the symbols, I JUST learned that you can type in きごう (“symbol”) and you get this awesome chooser.
So if you want to put an onsen mark into your document ♨, you can of course type おんせん, OR you can type きごう and look through the list.
Also, if you use a particular symbol a lot, say that onsen mark there, you notice how it’s moved over to the left column to make it easier to pick.
Life just got more symbollific.
And yes, damnit, that’s a word.