Eureka Seven centers around Renton Thurston, the fourteen-year-old son of Adroc Thurston, a military researcher who died saving the world. He lives what he considers a boring life with his mechanic grandfather in a boring town. He loves lifting, a sport similar to surfing but with air as the medium. He dreams of joining the renegade group Gekkostate, led by his idol Holland, a legendary lifter.
An opportunity to do so practically falls into his lap when a large mechanical robot, called the Nirvash typeZERO, and Eureka, a member of Gekkostate, crash into Renton's room. Renton's grandfather orders him to deliver a special part to the Nirvash, which releases the immense power dormant within the typeZERO. Afterwards, Renton is invited to join Gekkostate, where he quickly discovers that the behind-the-scenes life of Gekkostate is hardly as glamorous or as interesting as printed in the glossy pages of their magazine, ray=out. Only one thing makes it all worthwhile for him: the presence of Eureka, the mysterious pilot of the Nirvash. Renton, Eureka, and the Gekkostate embark on an adventure that will shape their future as well as the world's.
Eureka Seven works on a wide variety of themes throughout its story. One of the most prevalent themes in the series is racial and religious tolerance and harmony, which is carried through the characters' relationships as well the series' conflicts. Some of the other more global themes that the series covers consist of issues such as allegories of real world conflicts and wars, current political climates from Japan and abroad, depictions of various subcultures and related musical movements that span several generations, and ties to environmental movements. The series also covers other more personal themes such as parenting, and family, along with a very innocent view of puppy love or love at first sight from Renton and Eureka. Identity and protection play a huge role for Renton and Eureka, as both of them say, "I am me" in the series multiple times, and Renton has sworn to protect Eureka. Continuing with themes addressed in previous series, responsibility and guilt manifest most explicitly with repeating the phrase, "You're going to carry that weight." The series works these themes, as well as the theme of growing up and change, into the journey of Renton Thurston.