High Quality Content by WIKIPEDIA articles! Quantum Mistake (originally titled Change Guy) is a manhwa (Korean Comic), originally published in 31 volumes between 1998 and 2006. It was authored by Son Eun-ho and illustrated by Choi Myung-su. It tells the tale of two boys, Woo-Soo Choi and Kang-Too Jee, after their souls are accidentally switched into one another`s bodies.