Saiyuki (1999)

On present day Earth, the brotherhood of humans and demons (youkai) has been broken. A corrupt and evil demon, Gyumao, is performing experiments that combine human science and youkai magic, causing all demons to go crazy. Now, Genjo Sanzo, a trash-taking Buddist monk, is given a mission: Deliver a sacred scroll, the Maten Scripture, to India. For the journey, he is teamed up with Son Goku, a 500-year-old demon, Sha Gojyo, a red-eyed half demon human, and Cho Hakkai, a school teacher turned demon. Together, the four of them must travel to India, but the road ahead will surely be full of speed bumps, and demon attacks.