Since everyone but Molly is Japanese, pronouncing their names should follow Japanese language standards. NOTE: NOT a native Japanese speaker, only know enough to be dangerous if I were instructing kindergartners lol.
Vowels are the key to each sound in Japanese, and learning what the vowels sound like should be a big assist to guide your pronunciation. Consonants (with the exception of "n" which can be a stand-alone sound in Japanese) are used with a vowel. Plus there are a few English/Roman letters not used in Japanese (like "L", though "R" sounds like a slightly rolled combination of both L and R).
a= ah
e= eh (channel your inner Canadian!!!)
i= ee
o=oh
u= oo
So Io would be "ee-oh", Uta would be "oo-tah", Rin would be "leen/reen", Ami would be "ah-mee", Ayane would be "ah-yah-neh", etc.
Japanese also does not have emphasized/strong syllables in their multiple syllable words so each sound/syllable should be sounded with similar inflection throughout the word (i.e. Ayane would be "ah-yah-ne" and not "ah-YAH-ne" or "ah-yah-NE").
Here ends my first-grade level of Japanese grammar lesson. :duncecap: