Takeshi Okano (Japanese: 岡野 剛, Hepburn: Okano Takeshi; born May 9, 1967) is a Japanese manga artist. He is best known for his work illustrating Hell Teacher: Jigoku Sensei Nube, with Shō Makura writing the story. It has been adapted into two anime television series and a live-action television drama. He has illustrated several related works, including Reibaishi Izuna. Okano has also illustrated Digimon Next, while Tatsuya Hamazaki wrote the story.
Source: “Takeshi Okano”, English Wikipedia (CC BY-SA 4.0), excerpt