Choujyu Sentai Liveman

Choujyu Sentai Liveman is a Japanese television series. It is the 12th series in Toei's Super Sentai series.
New things.
It was the first Super Sentai series to have a female Blue Ranger as well as the first Super Sentai series that introduced animal-based mecha. It was also the first Super Sentai series that introduced a super-combined robot (that is 2 or more robots put together); the first Super Sentai series to have three members from the start, with two additional members joining later on; it was the last Super Sentai series that had its mechas transported to the battle through a flying fortress on a regular basis, which could not occur again until "Bakuryū Sentai Abaranger"; and it was the first Super Sentai series to have both a Green Ranger and a Black Ranger in the main five, as opposed to interchanging one with another. This did not occur again until "Engine Sentai Go-onger".
Plot.
Academia Island.
Academia Island is an elite school that various genuis students from across the globe attend. Among them are Yusuke Amamiya, Joh Ohara and Megumi Misaki who with Takuji Yano and Mari Aikawa sought to create a suit strong enough for space exploration. 
Conflict with friends.
However, three of their friends Kenji Tsukigata, Rui Senda, and Goh Omura felt their talents were being wasted. They decided leave to join an evil organization called Volt. Volt offers to raise their full scientific potential. As a result, when Yusuke and others saw them leaving, Kenji draws a gun on the three with Takuji and Mari talking the fatal blow. Soon after, Professor Hoshi pitches in to help Yusuke and his friends complete the suits so they can serve to prepare against Volt.
Present day.
Then in 1988, the present day, with Kenji, Rui, and Goh now known as Doctors Kemp, Mazenda and Obular, Volt begins its attack by devastating Academia Island. As a result, Yusuke, Joh, and Megumi take up the suits they created and become the Livemen to battle against their former classmates and Volt. 
They managed to get Goh to leave Volt. But Volt recruits new members in Doctor Ashura and the aliens Guildos and Butchy. Soon after, the Livemen are joined by Tetsuya and Jun-ichi. They are the respective younger brothers of Takuji and Mari, while learning that three is a darker agenda behind Volt that only its leader Bias knows.