I posted a thread similar to this one a while ago, but that one's an old thread now; and this is a new kind of question anyway.

I was just wondering, is it true that words are spelt by using the signs for certain sounds?
For example, if there are signs for "ma", "sa", "mu" and "ne", then can I just write those signs and thus spell the word "masamune"?

Oh, and one more thing:
what letters are used in the Japanese video games?
Kanji?