|This article is about a/an ally in Kamen Rider Fourze.|
Mari is very cheerful and enjoys taking pictures of people with a cheerful smile (i.e. Miura and Gentaro Kisaragi). She genuinely cares about her boyfriend and was really worried when he stopped coming to school and stopped showing his cheerful smile.
Mari helped Gentaro and the Kamen Rider Club try to convince Miura to come back to school and soon learn about his addiction to Cosmic Energy. It was a picture of Miura that Mari took that convinced her boyfriend to quit on the Zodiarts Switch. After the Scorpion Zodiarts was defeated, Miura joined Mari in the photography club.