Saiyuki(1999)

Saiyuki is an anime series set in a modern world where the peace between humans and demons has shattered. A corrupt demon named Gyumao conducts twisted experiments combining human science with youkai magic, driving all demons into violent madness. Buddhist monk Genjo Sanzo receives orders to transport the sacred Maten Scripture to India, a journey he cannot make alone. He assembles an unlikely team: Son Goku, a 500-year-old demon; Sha Gojyo, a half-demon with crimson eyes; and Cho Hakkai, a former schoolteacher transformed into a demon. The four must traverse dangerous terrain toward India while battling crazed demons and uncovering the truth behind Gyumao's sinister plot. Equal parts action and dark humor, Saiyuki blends supernatural mythology with buddy-comedy dynamics as this mismatched quartet confronts both external threats and their own troubled pasts.