(English) Ko wrote and illustrated her first picture book at the age of 39; she hasn't missed a day since starting work on her illustrations. She writes what she can't draw and draws what she can't put to words. Her publications include Spring Dream, Okchundang, Seesaw, Mumu's Moon Swing, The Story of an Old Goat, Raise the Guard, The Best Day Ever, and Mr. Cotton Pants' Cotton Pants. Ko has also published the young adult novel The Noise Inside Me and the prose works I Am Well and The Picture Book Mountain. Ko keeps busy telling her stories in illustrated form as well as essays, fiction, and comic books. 

(Japanese) 絵: 絵本作家として活動しながら文章では語れない話を絵で表現しています。

書籍には「私たちここにいます、動物園」、「ガードを上げて」、「ゾウおじさんは、鼻が手なんだって」、「鉄線ゾウ」、「お母さんなんで来ないの」、「五月の光州は、再び希望になる」、「もんぺおじさんのもんぺ」、「スーパーネコ」、「最高に素敵な日」、「元気だ」などがあります。

(Vietnamese) Tác giả hiện đang là họa sĩ sách tranh, vẽ nên những câu chuyện không thể dùng chữ để diễn tả.

Sách của anh ấy bao gồm 《We Are Here, Zoo》, 《Raise the Guard》, 《The Elephant Uncle Has His Hands》, 《Wire Elephant》, 《Tại sao mẹ không đến》, 《Super Cat》, 《The Greatest Day》 , 《Xin chào》, v.v.