Five siblings are chosen to protect the world from the evil Zone Empire. Will the fiveman bealbe to destroy him

In 1970, Doctor Hoshikawa was researching how to transform the planet Sedon into a green, lush world, testing it by attempting to grow flowers. On the day the first flower bloomed, the Zone Empire launched an assault on the planet, separating him and his wife from their five children. Arthur G6 took the five children back to Earth and raised them while after the attack, Doctor Hoshikawa is safely went to Planet P16 Milky way.