Yuusha Exkaiser

When aliens plan to invade earth, the young Kouta along with a giant robot from outspace named Exkaiser must team up to save the world and his friends.

Brave of the Sun Fighbird

In 2010, an evil Minus-Energy Lifeform called Draias has made his way to Earth, and allies himself with an evil scientist known as Dr Jango to create chaos and ruin the planet. A unit dispatched from the peacekeeping Space Police Force follows him to Earth, and their leader Fighbird inhabits the body of an advanced android built by Dr. Hiroshi Amano, becoming Yuutarou Katori. Katori and his team, inhabiting various Earth vehicles and accompanied by Dr. Amano's grandchildren Kenta and Haruka, fight against Draias's forces while adapting to life on Earth. (Source: Brave Series Wiki)

The King of Braves: GaoGaiGar

In the year 2005, a race of alien monsters called Zonders emerge from underground and launch a series of attacks on the city of Tokyo. The only defense against these creatures is the secret agency known as the Gutsy Geoid Guard (or 3G) and their ultimate weapon, the awesome giant robot GaoGaiGar. GaoGaiGar's pilot, Guy Shishio, is a former astronaut who was nearly killed two years before when the Zonders first crashed to earth. Guy's life was spared when a mysterious robot lion called Galeon pulled him from the burning shuttle and brought him to Earth. Guy's father, Leo, then used Galeon's technology to rebuild his shattered son as a cyborg, in the hopes that he could stop the aliens when they appear. Now, with Galeon as its core, GaoGaiGar fights to protect Earth. He is aided by a team of transforming robots and by a young boy named Mamoru, who has the power to purify the Zonders' cores, and seems to be connected to the mysterious Galeon. (Source: Anime News Network)

Getter Robo

From deep within the Earth's surface, the Dinosaur Kingdom make their move to wipe out mankind and conquer the planet with their mechanical dinosaurs. After a prototype Getter Robo is shot down by a mechanical dinosaur, the Saotome Research Institute decides to use the real Getter Robo, which is combat-capable. Due to a lack of pilots in the institute, Ryo Nagare goes to his college to persuade martial artist Musashi Tomoe and outcast Hayato Jin to join him and pilot the Getter Machines to combat the new threat and protect mankind. (Source: Anime News Network)

Shin Getter Robo vs. Neo Getter Robo

Years after the defeat of the Reptilian Empire, Getter Team has begun training on a new super robot, Neo Getter Robo. But a surprise attack from the Empire's revived leader forces them to recruit a street fighter named Go Ichimonji as Getter One's pilot. Faced with an enormously powerful foe, the new team's only hope for victory may lie in the resurrection of the lost weapon of humanity, Shin Getter Robo. (Source: Anime News Network)

Brave Bang Bravern!

Bang Brave Bang Bravern</I> is set in a world where humanoid armored weapons known as “Titatonostrider” (“TS” for short) are used in warfare. The story kicks off when troops from various countries converge on the island of Oahu, Hawaii, including the main characters, Ao Isami of the Japan Ground Self-Defense Force and Lewis Smith of the United States Marine Corps. Isami and Smith cross paths during battle, but suddenly their teams are attacked by an unknown enemy, scattering soldiers and sending their forces into disarray. In order to save their friends and survive on the deadly battlefield, they must fight with every ounce of courage and pride that they can muster. (Source: Crunchyroll News)