Choujuu Sentai Liveman (1988)

Academia Island is an elite school that various genius students from across the globe attend. Among them are Yusuke Amamiya, Joh Ohara, Megumi Misaki, who with Takuji Yano, and Mari Aikawa sought to create a suit strong enough for space exploration. However, three of their fellow classmates and dear friends, Kenji Tsukigata, Rui Senda, and Goh Omura, felt their talents are being wasted and leave to join an evil organization called Volt where offers them to raise their full scientific potential. As a result, when Yusuke and company saw them leaving, Kenji draws a gun on the three with Takuji and Mari taking the fatal blow. Soon after, one of the professors at the school, Professor Hoshi, pitches in to help Yusuke and his friends complete the suits so they can serve to prepare against Volt. Two years later, with that Kenji, Rui, and Gou 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. Though they managed to get Goh to leave Volt, the organization recruits new members in Doctor Ashura and the aliens Guildos and Butchy. Soon after, the Livemen are joined by Tetsuya and Jun-ichi, the respective younger brothers of Takuji and Mari, while learning that there is a darker agenda behind Volt that only its leader Bias knows.