The time was 1976... a new era building upon the previous years that highlighted the Justice League and Justice Society. And with a new era, new superheroes debuted to train beside seasoned mentors. The Justice League established a base on the surface of Earth-One, in Gotham City, wherein four of their number and one Teen Titan trained teen proteges Marvin and Wendy... and later alien Wonder Twins Zan and Jayna... under the team name "Super Friends". Though the Society members (such as Hawkman, Flash, Green Lantern, Wildcat, Doctor Fate and Doctor Mid-Nite) were fluid in their membership while tutoring these terrific teens, the League appointed Super Friends remained the same fabulous five. The tutelage of their four young apprentices mirrored that of the Junior Justice Society who aided their mentors versus the Injustice Society and a gang of juvenile delinquents.
Meanwhile, in the Gotham City of Earth-Two, the Justice Society had six of its number mentor the younger Robin, Star-Spangled Kid and Power Girl under the banner of the "Super Squad"... later recruiting a fourth youngster known as the Huntress. The actual non-canonical tales of the Super Friends mirrored those of the Young All-Stars... who themselves were the Earth-Two equivalent of the quartet of Superman, Batman, Robin, Wonder Wonder Woman and Aquaman.... whose's tales had a basis in the main steam universes. Nevertheless, an aspect of the Super Friends was also replicated in the Super-Squad, both short-lived groups that filled a niche and bridged the generational gap.
However, the Junior Justice Society were the Earth-Two counterparts of International Sea Devils of whom Nicky Walton was the most prominent member, himself one of the four original Sea Devils. They were aspiring young heroes on their world much as as the Junior JSA was on Earth-Two, led by Don Brent. In fact, it was Brent who led his teammates and their adult inspirations versus their arch enemies of the Crimson Claws, after their notable assistance defeating the first incarnation of the Injustice Gang of the World. Meanwhile, the International Sea Devils alongside their role models faced Nazi's, terrorists and sea monsters of varying shapes and sizes. Neither youth team met the counterparts of their adult mentors, as on Earth-One the Justice League dealt mostly with threats above the ocean...Aquaman not withstanding... and on Earth-Two the cosmic twin of lead Sea Devil Dane Dorrance, the Red Torpedo aka Jim Lockhart, mostly worked either alone or with his fiancee Meg.
Marvin White had a counterpart of Earth-Two who was also like him the son of the real Diana Prince, while Wendi Harris has a cosmic twin on that same world who was the wife of Rex "Hourman" Tyler. Zan and Jayna's dopplegangers on Earth-Two were Hansel and Gretal who, like the Wo der Twins, were aliens although they originated from Fairyland instead of Exor.. and met the Justice Society only once.