Captain Hans tells the story of a former astronaut who is assigned to teach space cadets. Although he's reluctant initially to take on the new task but the friendly and fun attitude of his cadets change his mind. Raju the silent cadet, Jun the curious one and Lee the hyperactive cadet will totally change his attitude towards teaching. Their adventure starts when Lee pushes the take off buttons that take the four of them to outer space and later crash onto an unknown planet. They are not the only ones stranded there as three aliens who were on their way to Earth to catch some humans for their leader's collection had also crashed. Balamon, Balimon and Babamon were excited to notice that they don't have to go all the way to Earth as they found four humans for the taking. Thus life on the planet turns into a classic tale of cat and mouse between the hostile aliens and humans. But the new planet offers so much more than new discoveries, unique scenery and new experiences for them as it also offers mutually beneficial relationships between both parties. They later find out that in order to survive in the planet they must learn to adapt and help each other.