Risa bonds closely to her love-rival because of their shared feelings of inadequacy compared to Kanzaki and a mutual love for ÅŒtani.
It is shown that her grandmother was very tall, standing taller than Risa at 6'5" 195.
Risa somehow misinterprets this and does not actually consider them to be dating for a short while until ÅŒtani is forced to make it clear that they are dating.
Her fashion sense is the same as seen in the anime and manga, and the school uniform she is seen wearing is the one from the manga.
Risa often looks to Chiharu as an innocent younger sister figure that she needs to protect.
And when I say always, I really mean ALWAYS.