The secret to Super Junior's 20-year friendship? Shindong and Heechul's spicy revelations and a surprising past.

Anecdotes like how Kim Heechul used to immediately cut ties by saying he would delete someone's number if he didn't like them even slightly, or the part where he wrote in a letter of apology during his trainee days, "I don't know what I did wrong, but I'm writing this because I was told to," really gave me a glimpse into his past lol.

The anecdote about Heechul, who went home crying because he felt wronged while Shindong was receiving group punishment for making a mistake during practice—since it happened to be his birthday—gives us a glimpse into just how intense dorm life was back then.