Friend zoned for 18 years. Can't we just start dating?

Whenever elementary school teacher Kang Joon-soo falls in love, he always gives too much of himself to the relationship. Yet despite that, he ends up being the one getting dumped by his girlfriends. Joon-soo has been friends for 18 years with Kim Hyun-woo, a weather forecaster whose beauty belies her witty tongue and aggressive manner.