My Love Mix-Up! – Kisskh English Subtitle

Timid and clumsy Atom has a crush on Matmi, 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 matters worse, Kongthap sees his name on the eraser that Atom drops and thinks Atom has a crush on him!

(Source: Kieta Hatsukoi MyDramaList; edited by MyDramaList)

~~ 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).