Konjiki no Gash Bell!!: 101 Banme no Mamono  

Gash Bell The 1st Movie: Unlisted Demon, Gash Bell Movie 1, Konjiki no Gash Bell!!: 101-banme no Mamono, Zatch Bell! 101st Devil, 劇場版 金色のガッシュベル!! 101番目の魔物

During summer vacation, Gash and his friends decided to go on a picnic at Fuji Mountain. While there, they met Kotoha, who had a white magical book with a message that Gash's mother was in a cave in the forest. However, when they found the cave, they encountered Wiseman instead of Gash's mother. In order to rescue him, Gash and his friends tried to venture deeper into the cave but stumbled upon an entrance to another world. The Black Knight soon appeared before them, thinking that Gash had stolen the 101st magical book. Now, Gash and Kiyomaro have to find the real culprit within 24 hours or be trapped in this alternate world forever.