After watching the cuts of her in the episode where she kisses the girl on the cheek and talks in Japanese, I must say I wasn't very impressed with the kiss. Her Japanese sounded good, she obviously has been learning the language and practiced those line for a while so she could have them down. I heard that her character is a lesbian because someone mentions it to Lee Dahae's character but the overall kiss scene with the girl who is her lover wasn't impressive. Without any knowledge of her character being a lesbian you would have thought it was a friendly kiss between friends. Even their interaction is something that friends would do.
I still give Jiyeon props for taking on that role.