The sweet love between Park Sung-hoon and Li Youjing. In the TV series My Three Sisters, Park Sung-hoon met the heroine Li Youjing at work, and they were attracted to each other and started a sweet relationship. However, this relationship is not favored by Park Sung-hoon's three sisters, who think that Li Youjing is a crafty woman and don't want her brother to be with such people.