| Cocoro Yumemi |
|Family|| Dai "Papa" Yumemi (Father) |
Youka "Mama" Yumemi (Mother)
Teru Yumemi (Brother)
|Voice Actor|| 豊嶋真 千子 |
She is Teru Yumemi's older sister. Always being full of vigor, they are often quarreling with each other. She is a grade 3 student and a Level 24 duelist. She became the Number 1 duelist on her first day at school by defeating Chishio in a "Creature Battle Duel" .
Cocoro uses a Light Civilization deck.