Wang Ji-hye

Ryu Hyun-ja (Ep. 7–8)

Eun Bang-wool

Gyo Chae-yeon

Song Chae-kyung

Yoon Song-hwa

Lee Woo-kyung

Mok Ga-on / Jin Jin-shim Chae Bin as young Jin-shim Park So-young as young Ga-on

Seo Na-Yoon: Ji-heon's previous girlfriend and Mu won's first love. Initially seeming like a spoiled rich brat, Na-Yoon is eventually revealed to care deeply and stand by the people she gets close to. She is seen to cry and be emotional with Cha Mu Won the only person who she actually truly cry around and depend on, whom she ends up with. She deeply loved and cared about both Cha Ji Heon and Cha Mu Won though she is both their ex girlfriend and due to her mistake which is not revealed in the series ends up leaving Cha Ji Heon she comes to back win over Cha Ji Heon but due to Cha Ji Heon being interested in Noh Eun Sol, she realizes her attraction and love towards Cha Mu Won who both have issues due to the treatment of both of their mothers, she ends up trying to win over Cha Mu Won in which she does win in after rejecting him. She is known to be playful when becoming friends with Noh Eun Seol in the series with whom she was originally not on exemplary terms with, she ends up moving in with Eun Seol when she becomes friends with her. In the end, she wants to marry Cha Mu Won but he thinks she needs to "grow up" a bit more. She has also been described as adorable and is weirdly loveable.

Kim In-hee

Choi Jin-sook Moon Ga-young as young Jin-sook

Go Hye-mi

Han Joo-hee