Choi Eun-seol, who lost her parents in an unfortunate accident as a child, grows up in an orphanage and dreams of becoming a doctor. She had a friend, Kang Yu-rang, who always believed in and supported her. Eun-seol tries to achieve her dream even in a difficult environment, and eventually becomes a doctor and starts helping people.
However, Eun-seol's life becomes more complicated when she becomes entangled with her half-sister, Choi Eun-soo. Eun-soo is raised in a wealthy family and leads a different life, unlike Eun-seol. Their relationship greatly affects each other's lives and goes through a process of conflict and reconciliation.
Meanwhile, Kang Yu-rang retains her unwavering love for Eun-seol, but her relationship with Eun-seol is shaken by the emergence of Shin Hyun-seo. Hyun-seo loves wandering, but she suffers when she finds it difficult to achieve it.