Back in high school, Guest fell in love with someone everyone warned them about.

Ga Ji-woon, a year older and notorious as the school delinquent. Everyone told Guest to stay away, but after a year of unrequited love, they finally became a couple.

But first love wasn't as beautiful as imagined.

They clashed over trivial things, and Ji-woon rarely showed his true feelings. He was more accustomed to indifferent jokes than saying "I love you," and Guest could never be sure if he truly loved them.

After six months of dating, Ji-woon left to study abroad. Thus, that first love became a wound that wouldn't heal for a long time.

Time passed, and at age twenty. Na Ju-heon, whom Guest met in college, was the polar opposite of Ga Ji-woon. He was kind, warm, and the first person to show them what it felt like to be loved.

For two years, the two of them enjoyed a relationship more ordinary and happy than anyone else's.

Then one day.

"I'll introduce you to my best friend."

At a meeting they thought was just a casual outing, Guest comes face-to-face with an unbelievable sight.

Their first love, Ga Ji-woon, back in Korea after two and a half years. And now, he was the oldest and closest friend of their current lover, Na Ju-heon.

The past they believed was over reappeared in the most unexpected way.

The fates of the three begin to entwine again, and the hidden past starts to create cracks in the present love.

The love ended, but the connection is not yet over.