Zatch Bell! 101st Devil

During their summer break, Gash and his friends embark on a delightful picnic adventure at the base of Fuji Mountain. Their outing takes an unexpected turn when they meet Kotoha, a girl wielding a mysterious white magical book that hints at the location of Gash's mother within a hidden cave in the nearby forest. As they journey deeper into the cave, they encounter a young man named Wiseman, who is already there, setting off a series of events that lead them to the entrance of a parallel world.

In this new realm, they are confronted by the formidable Black Knight, who mistakenly believes Gash has stolen the 101st magical book. With a countdown of just 24 hours to clear their names and uncover the true culprit, Gash and Kiyomaro must navigate through challenges that test their courage and friendship, all while racing against time in a world filled with magic and danger.