Joy of girl group Red Velvet is collaborating with popular Naver webtoon “Guide to Proper Romance" to release a themed soundtrack on April 15, production company Toon Studio said on Thursday.

Titled “Why is Love Always So Difficult?” (translated), Joy’s song represents the state of mind of the female protagonist Bareum who faces difficulties when it comes to love.

“Guide to Proper Romance,” written and drawn by cartoonist Namsoo, is about college sophomore Bareum, who has spent her whole life sticking to a set plan but realizes that her romance with a fellow student isn't going to work out how she hoped. The webtoon currently has a rating of 9.97 out of 10.

The collaboration with Joy marks the webtoon's 14th time to work with a musician. Other artists that have participated are Lee Hi, Xia Junsu, Jukjae, Loco, 10cm, Yoonha, Lin, Heo Gak, Yang Yo-seop and Jung Eun-ji.

Joy’s track will be available on various music streaming websites from 6 p.m. next Thursday.

BY LEE JAE-LIM [lee.jaelim@joongang.co.kr]