Several successful manga started out as one-shots that were picked up. Komi-san comes to mind, and Nagatoro was a short 5-chapter before becoming the basis of the successful manga and anime it is today. This one just didn't attract attention. It's cute and I'd like to watch their romance but there's no hook to make it stand out from others like it.
Seinen, pff. It's some uninspired cliché about a delinquent girl who latches onto a nerd and softens up. I wish the whole plot she were dragging him by the chinchin as hard as the tough guys in manga from the '90s.