Leiko Tanaka (麗子 田中 Reiko Tanaka), alias Go-Go Tomago, is a member of the Japanese super-team, Big Hero 6. She is young and highly aggressive, with little patience for others, but a very strong will, someone who does not give up easily. She is also known as the hothead of the team as she tends to act on her aggressive tendencies without considering the results. GoGo was apparently drafted into BH6 rather than facing jail time. The nature of her criminal convictions is unknown.  She joined to prevent Everwraith from slaughtering millions in downtown Tokyo. During the battle, Big Hero 6 was joined by Sunfire, Japan's premiere super hero and a mutant with the ability to super-heat matter into plasma, who was instrumental in the Everwraith's defeat.
Soon after, Big Hero 6 moved their headquarters from the Giri Office Building to Japan's Cool World Amusement Park, where they were attacked by X the Unknowable, a monster born from a child's drawings that could transform its atomic structure into any form and shape. With the help of Alpha Flight, Big Hero 6 destroyed X the Unknowable in the fires of Mount Fuji. Afterwards, Big Hero 6 continued to protect Japan from all threats, such as when the team rescued Tokyo residents from a freak blizzard caused by the Crimson Cowl (Justine Hammer) and her Masters of Evil.
The members of Big Hero 6 fell victim to a mind-control device implanted within Baymax. Traveling to Canada, the mind-controlled super heroes attacked a new incarnation of Alpha Flight at a national park. After a brief battle, the mind-control device was short-circuited and the two teams parted as friends. Big Hero 6 returned to Japan to seek out the parties responsible for their mind-control.
Big Hero 6 help Alpha Flight protect the timestream.
Spider-Man rallies many of earth heroes including Big Hero 6 to help stop the construction of Doctor Octopus' satellites.  Big Hero 6 found one of the facilities, discovered that it is guarded by Everwraith. Despite a tough battle, Big Hero 6 finally ended up victorious.
Go-Go Tomago Battlesuit: The Go-Go Tomago battle suit is a voice-activated device that absorbs and amplifies kinetic energy, enabling it's wearer to temporarily transubstantiate his or her body mass into thermochemical energy simply by uttering the trigger words "Go-Go Tomago".
Go-Go Tomago is a skilled motorcyclist and an accomplished racer and stunter. She has also several contacts in Japan's criminal underworld, as many of her former associates are unaware that she secretly serves as a member of Japan's premiere super-hero team.