umbraregis:

…does it count as a gary stu if my OC had a crush on Yoh and it was onesided.

Out –;; No. Even in the manga and show a girl Tamao had a one-sided crush on Yoh. Only a Stu if all boy/girlss magically fall for your OC. 

What do the the rest of my SK buddies have to say? 

EDIT: People have agreed. Everybody has feelings to have a crush, will notmake you a Stu.