This paper summarizes the internal and external contexts of Mizuki's creation of yokai, which is at the peak of the current yokai boom in Japan and consists of three main elements. He was conscripted during the Pacific War and witnessed the deaths and “disfigured bodies” on the battlefield of Rabaul. It is clear that what he felt from the death and damaged bodied he witnessed at this time was the ‘wonder’ of the dead. This is because the “wonder” of the lion is the fundamental starting point that led to the development of Japanese Yokai formatives. In other words, Mizuki's case was no exception. Mizuki pointed out and criticized the horrors of war and the structural absurdity of barrack life in various cartoons based on his war experiences. His feelings of anger, resistance, and despair against war are sometimes clearly reflected in the yokai painting, sometimes in shades. Ironically, however, it can also be said that his experience of war was a period of 'softness', a process that raised him as a master of ghost comics. Mizuki's experience of war has a significant impact on his creation of a yokai, which bears certain amount of ‘death’ in its form as an invisible supernatural being called ‘youkai.’