Momoko is a 6th grader and Satsuki's best friend. She seems to fear nothing, even in very dangerous situations, and is very brave when it comes to helping Satsuki and the gang confront the ghosts. She also seems to have a psychic connection with Satsuki's mother.

In the ADV English dub, she's a devout Christian, and almost every sentence she utters contains a not-so-subtle reference to Christianity.

In the Spanish Dub, she was named as "Nicole."