Tokio is a junior high student living in the present time who is recruited to be a member of the 24th century's Space-Time Administration Bureau. Together with his partner Calen, their mission is to uncover the "True History", the part of history that the textbooks doesn't tell. But in their way is the Akudama Trio that intends to prevent the True History from being revealed for their own personal gains. (Source: Wikipedia)
9Anime is the best site to watch Time Bokan 24
SUB online, or you can even watch Time Bokan 24
DUB in HD quality. You can also find Tatsunoko Production
anime on 9Anime website.