With the novel I'm currently writing, there are three names that start with M. One's the antagonist, one is the protagonist, and the other one is antagonist turned protagonist- the names are Mason, Mosire, and Maliko. (Maliko and Mosire are both the last names of the characters, but that is how they are referred to as in the book). The question is, should I change at least one of these character's names?

4 answers

Yes, unless you have a solid reason for beginning their names with the same letter.
Awesome, thank you!
You're welcome.
I absolutely agree with Ms. Sue. Unless you want that to mean and/or represent something important. Having them all start with the same letter will probably result in your readers, well, reading into it too much. Good luck with your book!