Yui Kotegawa Is the Main Antagonist of Adventure in Japan Arc. She is the head of the School Disciplinary Committee. She is Lorcan's Ex-Girlfriend and Lilly's Worst Enemy.
After Mrs Tweedy's Defeat, She Almost die after Being hit by a Car and Nemesis Offers Her 4 Numbers and 2 Chaos Numbers and a Ci Number. So She Accepts and uses them.
A Tale of Cillian Darcy Half 1: Barians RevengeEdit
Yui Appeared as an Friendly Disciplinary Commettie Chairman and Introduce to Lorcan and Lilly as their New Friend and Tour Guide on Their First Day of School. Until then Their Enemy the Society of Light Arrived and Announce they are About to Have their Final Battle until She Turns on Lorcan and Lilly for the Ultmate Power
Quest for Numeron DragonEdit
She Shocked that She has an Numeron Power of the Queen. so She Became a Numeron Queen if She'll Find Number 100, so She'll vow to Defeat Cillian Darcy
Yui Uses a Disciplinary Deck in the First half, And as the Main Antagonist, She Use a Numeron/Numerronius Deck.
|Rito Yukki and Lala Deviluke||Win (W/ Lorcan)|
Action Duel DeckEdit
Yui Use her Battleguard Deck against Cillian in the Final Battle