This drama tells the story of a mom who stays with her children again after her children become jobless.

Na Moon Hee is the owner of a noodle shop. Her already independent children stay in their own houses. But after becoming jobless, her children come back home again and work together in her noodle shop.

(Source: koreandrama.org)

“大发面店”的女老板罗文姬与大儿子正学、大学讲师儿媳美善和孙女赛纶生活在一起；二女儿书亨与小说家承修结婚后从家中独立；三女儿智慧则一边在超市打工，一边计划着自己的未来。看似平凡的这一家子自从大儿子被炒鱿鱼成为待业者、二女儿一家的出版社事业失败后，都纷纷回到罗文姬的家里一 起生活。而唯一一个有着人生目标的三女儿智慧确是儿时被抛在罗文姬家门口的弃婴。

经过各种挫折后失败的孩子都回到了原来的家中，但每个人并没有好吃懒做：书亨在收银台负责收账，还指使正学一边在厨房打工，一边去还债。《妈妈是什么》讲述了以自己的原则对待家人的罗文姬与子女们生活在一起后发生的一系列故事。