Just to elaborate on the above comment on The Amazing 3.
The mission of Patrol A3 was not just to observe human activity on the Earth in a passive manner, but to determine if the human race would become a threat to interstellar peace because news of the wars and violence on this planet had reached the Galactic Union. Therefore Patrol A3 came equipped with a "anti-proton" device that would be capable of wiping out the entire population of the Earth if a final judgment by the Union weighed against the Earth.
The names and ranks of Patrol A3 as follows: Capt. Bonnie, Corporal Ronnie, and Lt. Zero -- upon landing on Earth they assumed the disguises of Earth animals, namely a bunny, a horse, and a duck. While conditions on Earth would continually shock the aliens, Capt. Bonnie and Ronnie were the most tolerant, whereas Zero was always ready to detonate the bomb and go home, seeing little to no value in Earthlings than their music (and he often played a guitar in the episodes) and Ronnie being the gluttonous one, liked Earth food.
The boy who became A3's companion (not "Jimmy") is Kenny Carter, (voiced by Kurt Nagle) and his brother Randy Carter (Agent P-77) is an agent of the Phoenix Agency for Peace Enforcement.
Many of the episodes then, would revolve around P-77's adventures fighting enemies like "InterSpy" and often Kenny and the A3 would come along his save his neck -- in fact Kenny was once awarded the honorary title of "Fledgling" by "M" the head of Phoenix for helping his brother on many occasions.
Osamu Tezuka was truly a genius of his own time. Granted, much of Tezuka's manga and anime works found inspiration from earlier works of others that he enjoyed or respected, Jules Verne, Walt Disney, etc... But the story of Wonder 3 or The Amazing 3 is quite fresh and original and one the best works of his imagination.