"People cry, not because they're weak. It's because they've been strong for so long."

Park Chanyeol does not do sadness, he tries to find at least a little bit of happiness in every situation good or bad and the next thing you knew, he's laughing and smiling so hard that you can't stop yourself from laughing and smiling like an idiot as well. That's why he's called the happy virus.

But the truth is, he's slowly losing it. He can't keep his sadness to himself any longer and one day, he just snaps leaving his band members in the state of shock, yet all they thought was that Chanyeol must've been in a bad mood and dismisses the subject.

Days, hours and finally weeks pass and they soon notice that their happy virus isn't there anymore. All that's left is an empty shell of the person he used to be. Nobody knew the source of his sudden change of personality. Heck, not even his best friend, Byun Baekhyun, knows!

Will they finally know why he's acting like that? Will their 'happy virus' return? Will he smile again? Will he return to the Park Chanyeol we all know and love? Or will he stay like this; broken, alone, lost and unsure?