In February, Masafumi Yamagishi, a 2-year-old resident of Edogawa Ward, was found bleeding and collapsed, and the Tokyo Metropolitan Police Department arrested Kosuke Omoto. A mask with blood stains believed to belong to Omoto was found in the residence at the scene.
The teacher told the interviewer before his arrest that he had a nosebleed when he entered the man's house before, but the police believe that there are unnatural points in the explanation.