Boys Over Flowers star Goo Hye Sun sang a duet with Seungri on Lee Hana's Peppermint on March 6th. They sang Kim Gun Mo's Sleepless on a Rainy Night together and she also played one of her own compositions. Their voices kind of sound alike! Later on during an interview, Goo Hye Sun said that F4 members all had very nice personalities and just like on television they had charming dispositions. Co-star Kim Hyun Joong is blunt but tries to hide it and has become a close friend to her. She also mentioned that even though Kim Bum, although the youngest F4 member, was very mature and manly. Kim Joon is very quiet in real life and he and Kim Hyun Joong still speak formally to one another. She also confessed that she's starting to fall for Goo Jun Pyo's personality after filming with her even knowing it! Goo Hye Sun considers Lee Min Ho to be not only like a little brother to her but also a good friend. She also stated that she thinks equality is important in a romantic relationship. Although a lot of women may sympathize with her already, but a lot of relationships lack that quality of fairness. The actress/singer feels that all people want that feeling from their partner that "this person is my person" and will take responsibility of them to the end. Thanks to Deanna and heenimxluv for the tip.