Muhyo & Roji's Bureau of Supernatural Investigation (Original Japanese Version) Season 1 Episode 11 The Gamble

Rio continues her relentless attack on Muhyo and the others, refusing to even listen to the fervent pleas of her own pupil, Bico. Those who have sold their souls to a messenger of Hell using forbidden magical law can never be human again... but Muhyo says there may be something they can do for Rio. However, he needs to recover from his mental numbness in order to do it. Backed into a corner, the team gambles everything on a secret formula concocted by Bico to help him temporarily recover...