Japanese words and names, when translated to English, are written and pronounced more or less phonetically. However, vowel sounds and stress patterns may not be natural to English speakers, particularly when vowels are placed next to each other.
It is best to keep in mind is that the Japanese a is a long syllable (as in father), e is short (as in bed), and i sounds like ee. Thus, the name Aomame would be pronounced "ah-o-mah-meh."
English speakers also tend to pronounce three-syllable Japanese names by emphasizing the middle syllable; this is usually incorrect. The stress is most often meant to land on the first syllable. For example, the Japanese author Haruki Murakami is pronounced "HAH-ru-ki" as opposed to "ha-ROO-ki."
The prolific translator Jay Rubin includes a macron (ō,ū) symbol above vowels that, in certain words, are meant to be emphasized as a long syllable. As a result, Rubin's translation ("In a Bamboo Grove") spells the bandit's name as Tajōmaru.
Rubin also prefers to write an author's name according to the Japanese convention of putting the surname first. Thus, the author of "In a Grove" is written as Akutagawa Ryūnosuke ("ah-koo-tah-gah-wah ree-ooo-no-soo-keh").