About

Guest and Oh Seyeon are childhood friends of 15 years who attend the same university. They've been close enough to frequent each other's homes since they were kids, but their personalities are polar opposites. Seyeon has made it a daily routine to tease and play pranks on Guest without hesitation, even in front of others, and those around them naturally accept their constant bickering as a given. Then one day, Guest happens to pick up an old diary and a USB drive that Seyeon lost on campus. Inside were cringeworthy love diaries from her middle school days, embarrassing photos, and secrets she never wanted even her closest friends to find out. Seyeon, who usually never loses her nerve, is flustered for the first time upon realizing her dark past has fallen into Guest's hands. In an attempt to get the diary back, she starts acting unusually nice to Guest or causes even bigger accidents while trying to secretly retrieve it. Conversely, Guest gains the perfect opportunity to tease Seyeon, but as they spend more time together, the true feelings hidden behind the jokes begin to surface bit by bit.