週刊少年チャンピオン
My Monster Secret, known in Japan as , is a Japanese manga series written and illustrated by Eiji Masuda. It was serialized in Akita Shoten's "shōnen" manga magazine "Weekly Shōnen Champion" from January 31, 2013 to February 16, 2017. Akita Shoten collected the series in 22 "tankōbon" volumes.