Kazuo is the grandmaster of Japanese horror manga. He published his first manga while still at high school and began working professionally in the field after his graduation. His first creations were 'Betsu-Sekai' ('Another World') and 'Mori-no-Kyoudai' ('The Brother and Sister in a Forest'). He mainly created his works for so-called Kashi-hon, magazines that were not for sale but for rent. He developed his detailed horror style in 1962, when he settled in Tokyo. His works 'Kuchi ga Mimi made Sake-ru Toki' ('The Moment The Mouth Tears to Ears'), 'Hebi Shoujo' ('The Snake Girl') and 'Hito-kobu Shoujo' ('A Girl Who Has A Human-faced Lump on Her Cheek') were his first claims to fame as a master in the horror genre.
In 2018 he was awarded the Prize for Inheritance at the Angoulême International Comics Festival for the French translation of Watashi wa Shingo. This was the second prize awarded him throughout his career and Umezu had previously been unhappy about the amount of recognition he had gotten for his work. The award motivated him to start working again and he produced a series of 101 paintings based on Watashi wa Shingo called Zoku Shingo: Chiisana Robot Shingo Bijutsukan, which were exhibited for the first time in 2022 and were his first new work in 27 years.
He passed away due to stomach cancer on October 28, 2024.
