My Love Mix-Up!

Atom has a crush on Matmee, the girl who sits next to him in class. He despairs when he borrows her eraser and sees she's written the name of another boy—Kongthap—on it. To make things worse, Kongthap sees his name on the eraser that Atom dropped and thinks Atom has a crush on him! 

 Adapted from the manga "My Love Mix-Up!" (消えた初恋) written by Hinekure Wataru (ひねくれ渡) and illustrated by Aruko (アルコ).