The Earth Defense Class (地球防衛組 Chikyū Bōei Gumi?) is the name of the 3rd class of the 5th Grade in Hinobori Academy, which took that name after being given control of Raijin-Oh by the legendary warrior Eldran . They protect the Earth from the Jaku Empire's attempts to take over it.
All 18 members of the Earth Defense Class have a medallion given to them by Eldran that allows them to operate the robots in their possession. While Jin, Asuka, and Kōji are the pilots of Raijin-Oh and keep their medals in their Raijin Braces (as they allow the combination into Raijin-Oh), the remaining 15 students must all be present at the command center (which is Class 5-3) in order for their operations to proceed without problems. If even one of them is missing, it could prove fatal for the whole group as every function each of them serves is crucial to the success of their battles.
In Class 5-3 of Hinobori Academy, there was a bunch of normal students in a class session with their teacher after school was over (on a Saturday). Kōji saw a light coming from a volcano (which was Ken-Oh) going up into space. After forming Raijin-Oh and being struck down in a battle with Belzeb, Eldran was sent crashing down to Earth and fell on Class 5-3. He then introduced himself as the ancient warrior of light who protects the Earth, and then gave the whole class that duty in his stead, along with the power to operate Raijin-Oh as he was weakened and needed rest. So the whole class received the Raijin Medals, and in the middle of the night, their class and the ones below it were converted into the base, and the rack field, gym, and swimming pool were all made into launching points for the individual mecha that comprised Raijin-Oh.
The next day, their first battle came. Their medals caused them to feel that they had to assemble at the school, and Jin was surprised to see everyone else there on his way. Kōji called everyone inside their classroom where a star shape on Maria's desk was glowing, and it was in the shape of her medal. She put it in, and the class transformed into the base for the first time and went underground. The rest of the class members found their own desks glowing in the shape of their medal, and insert them into it, which made the computers open up. Meanwhile, for Jin, Asuka, and Kōji, rather than inserting their medals into their desks, said desks open up and the Raijin Braces attach to their wrists, which open to reveal places to put their medals. When they do, their desks move, and the three are taken through different chutes (which materialize their pilot suits on them) into their respective mecha units, which take off from their launch areas. Once they defeat the first Jaku Beast after some difficulty, Mr. Shinoda sees the robots with the children and is surprised. He asks why and they say it was forced on them.
A while after, General Takeda, the chief of the defense force, interrupts a meeting held by the class to decide whether they want to protect the Earth or not, and he demanded that they hand over Raijin-Oh to him. However, the principal says he can't launch an investigation while class is in session. Near that time, a Jaku Beast appears, and the Earth Defense Class tries to set off but the general stops them. Jin however manages to convince the class that they can't always listen to adults and that they can at least do good things on their own as well, and then they all agree. General Takeda isn't too happy with this, but then Mr. Shinoda takes the side of his students, and they are allowed to move out. After they defeat the beast, the General has no choice but to leave the protection of the Earth to them.
Other Members of the EDC
He is the operator of the starting system of the core robots and the weapons selector for Bakuryū-Oh.
Yoshiaki "Yoppa" Ogawa
He is Ken-Oh's circuit-based monitor and Bakuryū-Oh's transformation manager.
He is Ken-Oh's circuit system monitor, the launcher of Bakuryū cannon fire, and the main mechanic of the robots.
She is a commander in the Earth Defense Class and the main pilot of Bakuryū-Oh
Orie "Potato" Ishizuka
She is Hou-Oh's sensor systems monitor and Raijin-Oh's damage counter.
She is the energy gauge manager, launcher of Bakuryū Cutter Fire, and safety manager of Bakuryū-Oh's weapons.
She is an operator within Raijin-Oh.
Yōko "Cookie" Kuriki
She is Raijin-Oh's radar operator.
He is also a radar operator for Raijin-Oh.
She is Juu-Oh's sensor systems monitor and Bakuryū-Oh's damage counter manager.
She is Ken-Oh's system monitor, and Bakuryū-Oh's pulse checker.
This is a Bracelet-type piece of equipment worn by the three chosen pilots of Raijin-Oh, namely Jin, Asuka, and Kōji. They keep their medals inside there and transfer them to the Raijin Commander when it's time to combine. It also serves as a communication device.
A command terminal device that the Earth Defense Class received from Eldran. It has the ability to launch any of the 3 component robots of Raijin-Oh from anywhere the signal was activated, like a remote control. It is also used to begin the combination into Raijin-Oh when all 3 medals from the Raijin Braces are inserted into it. Tsutomu Kojima mostly holds on to the commander outside of operations, using it as a handy personal computer for inquiry and analysis.