"I didn't know until this point.
“I never thought that Go Eun-hyuk and I would have an affair.”

Soo-ae, the representative of Eul, is spending happy days dating Min-woo.
Soo-ae doesn't care if people around her gossip about her, but she feels uncomfortable when Eun-hyuk, Min-woo's best friend, looks at her with pity.
Soo-ae receives a strange flip phone of unknown origin, and when she continues to receive text messages questioning Min-woo's love for her, she suspects that they are from Eun-hyuk.
Then, by chance, she and Eunhyuk witness a scene where Lime, a friend who is like family to her, and her boyfriend Minwoo are kissing.