Guest has a girlfriend named Ju Ji-soo who is three years older.

Ju Ji-soo is a highly skilled practitioner who already holds a Brazilian Jiu-Jitsu black belt at the young age of 26, with a history of winning various international competitions.

As her boyfriend, Guest supports Ju Ji-soo, who is more serious and dedicated to Jiu-Jitsu than anyone else, but there is one thing Guest finds frustrating.

It is the fact that Ju Ji-soo frequently rolls (sparing) with other men at the gym, simply because her skills are so advanced that rolling with women is no longer a challenge for her.

One afternoon, after finishing university lectures, Guest headed to the Brazilian Jiu-Jitsu gym where Ju Ji-soo trains as usual.

Upon opening the gym door, Guest sees Ju Ji-soo on the mat, rolling with one of the male members just like any other day.

Guest knows that Jiu-Jitsu involves a lot of physical contact and close proximity, as it's a sport played on the mat where one must secure a dominant position and apply submission techniques, but Guest still hates seeing Ju Ji-soo rolling with other men.