Clear from his naming of Oni (Japanese demon or fearless), he was a man who played by the books when it came to the rule of law and he was also strict with others as well, but he was fair and honest regarding the distribution of rewards, plus, he wrote the laws in kana (the Japanese syllabaries) and made the interpretation simple for the convenience of the general public.
鬼の名を取るように、法に対して厳格な人物で他人に対しても厳しかったが、恩賞に対しては公平清廉で、法令に対しても仮名書きでわかりやすく書いて民衆に触れやすいように記したと言われている。