ジェフ・ジョーンズの冒険 - モンスター・ガーディアン！ (Romanzied: Jefu jōnzu no bōken - monsutā gādian!, translated: The Adventures of Jeff Jones - The Monster Guardian!), known in international markets as Jeff Jones: Monster Man, is a 1989 Japanese anime produced by Tokyo Movie Shinsha and Sony Music Japan. An English dub was produced by TransCanadian Audio Services, Inc. and ESM International Dubbing Inc. for Sanford Productions and the ITC Entertainment Group in 1991 and syndicated to TV stations across the United States and aired on CBC in Canada.
Jeff Jones (voiced by Yōsuke Akimoto in Japanese; Jake Sanford in English), the main character and a well-known "Monster Guardian" known for his excellent dancing skills and friendship to monsters and other crazy creatures.
Umeko Izumikawa (voiced by Yūko Mizutani in Japanese; herself in English), a Japanese-American friend of the Jones trio.
Ono Izumikawa (voiced by Michiko Nomura in Japanese; Lisa Yamanaka in English), Umeko's little sister. Ono was so popular with the staff of the original show that she was added into the American series.
Robert Stainton (voiced by Ikuko Tani in Japanese; himself in English), one of Jeff's friends and a crazed, brain-dead inventor.
Mina (voiced by Runa Akiyama in Japanese; Susan Glover in English), a cat friend of the Jones trio and their friends. She is Siamese, and Jack is shown to have a crush on her. Mina eventually appeared in the American show, but as a recurring character.