How to make added strings works with regular strings

If you see my UTF-8 reader, you can see that I managed to make it compatible with regular strings. Line #69 is the key here, and I'll reproduce it for you:
return ToString(res);
Yes, if you use ToString, then the result will be completely compatible with regular strings!

/r/DNHTIL

TIL that if you try to yield in @Initialize, Yukari will gap into your house and eat your brains.

Rectangle Horror

Thanks to Achy from LOCAA.

"the one above has a correct rect, and the one below should have a pixel from the bullets next to it stuck on it." - Achy

Wait, I don't get it. Is the top really supposed to look like that, or did you mess up the order? Probably the latter.

Elaboration:

For the red one I have (1,1,9,9)
but those 9's, other bullets are starting on them
so why are pixels from them not showing up>
[02:11:59] Achy: And with the orange one above...

(9,1,16,8)
the bullets on screen are 8x8

More about string adding

For the ignorant

I hoped that the behavior mentioned in my previous post could be the way to get around wonky Unicode reading in mkm's binary file functions until pre7 is finally released.
But arithmetic operations on strings returns a completely different type of string incompatible with ordinary strings. So ("A" + "!" - "A") == ("A" + "!" - "A") returns true, but ("A" + "!" - "A") == "!" gives an error.
So mkm can write a great danmaku engine, but he can't get typing quite right.

Apparently Danmakufu treats strings like arrays of their character codes...

And the results are hilarious.