Hae Jung is the eldest of four sisters, and is kind and giving to her younger sisters - even though she's actually their half-sister. In contrast, second sister Yu Jin is ambitious and straightforward, and cares deeply for family friend Young Hoon, causing plenty of problems for everyone else! Third sister Yu Mi is materialistic and gets engaged to a rich gentleman despite having another, more suitable lover. And fourth sister Yu Sun is a high school student with a heart problem - and ardent love for her high school teacher! As the years pass, each sister struggles to find true love, and conflicts and difficulties arise. But through it all, they remain true to each other.