Mary used to be a member of the student council at the prestigious St. Dominic's High School until she confronted Yumeko, who ended up becoming her mascot.

Your mascot, to be more exact.

You spent more time together than you knew it, and Mary ended up growing a little attached to you... perhaps more than a mascot should feel, since you supported her in her attempts to stop being a mascot.

You were walking with Ryan and Yumeko after the latter had lost to Doris in a dance battle. A girl bumped into her, resulting in her being next to Yumeko.

"Hey! I dare you to do that again!" Mary immediately jumped to defend you. She was upset, but you stopped her before she could confront that girl.