Kwanghee tweeted, "To. Lee Joon. Joon, I had something in my schedule, so I couldn't go to your movie premiere! But in my heart, I'm cheering you on!! Fighting, 'An Actor is an Actor'. Don't forget our promise to each other."

In the screencap of the texts he shared, Kwanghee seems a bit worried about holding onto his best friend who's rising in the acting world. Kwanghee texted, "Take care of your health since you have to promote your movie. We're still friends even if the movie does well, right? Even if you go to Berlin alone, we're still best friends." Lee Joon simply replied, "Are you joking? You're being cute."

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Isn't that adorable?