Song Na-Young, a 29-old-single mom, goes through the baby care with help of three best friends of her late husband. Na-Young, born with natural optimism and somewhat recklessness, just lost her husband and depends on three distinctive characters. Han Su-Hyung is a competent fund manager and most successful among friends, but most narrow-minded and stingy. Gwanghui is a handsome cartoonist with good taste of fashion, but an ultimate cynic. Gyeongtae is a young and good-looking detective, but too shy to speak in front of girls. Three guys at first feel burdensome when Na-Young asks for support. As time goes by, however, they start to feel a deep emotion toward the baby and to Na-Young as well.