KARA's Goo Hara apparently knew Super Junior's Shindong from way back in the day.

While guesting on the SBS variety program 'Strong Heart',�Goo Hara�confessed, "I knew Shindong before debut." She began, "When I was a trainee, Shin Dong walked me to a subway station." Goo Hara explained, "Shin Dong originally offered me to buy me dinner, but when I declined, he said he'd walk me to a subway station." She added, "I guess he liked me as a little sister." Guests on the show, however, questioned Shindong's intention by saying, "You don't walk someone somewhere because you like her as a little sister." Source: Naver