Armed Detective Agency members discuss the most suitable candidate for the second-in-command. Doppo Kunikida is carrying out official errands as planned in his diary as usual. Unexpectedly, a bomb-related incident occurs, challenging the ideals he has always upheld. When weighing one life over hundreds, how will he proceed?

15 children, 8 boys and 7 girls, are enjoying their summer camp together when they suddenly discover a grotto by the sea. When they enter the mysterious place they find a room full of computers, as well as a man named Kokopelli, who introduces himself as the owner. He claims to be working on a game which involves a giant robot that has been designed to protect the Earth from 15 different alien invasions. Kokopelli hasn't been able to test the game yet, so he persuades all but one of the children to sign a contract in what he claims will be a fun adventure. However, as soon as the contracts are signed things start to take a much darker turn. In Bokurano, the children must now pilot the giant robot Zearth one at a time in the hopes that they will have what it takes to defeat all of the upcoming enemies. But Kokopelli has left out one very important piece of information: the giant robot Zearth's energy source.

Saya Otonashi is a seemingly ordinary girl living a mundane life with her adoptive family in Okinawa City. In fact, her only peculiarities are suffering from anemia and being unable to remember any of her life beyond the previous year. However, Saya's forgotten past quickly comes back to haunt her—one night, she is attacked at school by a creature that feeds on human blood. Just when all hope seems lost, a mysterious man named Haji appears and fends off the creature temporarily. But when her rescuer forces her to drink his blood, Saya suddenly enters a trance and slays the monster with ease, using her own blood as a catalyst. Saya then learns of an organization named Red Shield, founded for the sole purpose of defeating the hellish beasts. Now Saya and Haji must work together with Red Shield to fight these fearsome monsters and unlock the secrets to the girl's past.

The atmosphere in True Cross Academy is lively and boisterous in the days leading up to the grand festival held once every 11 years. During this time, Okumura Rin is entrusted with the responsibility of suppressing the berserk Phantom Train. In the midst of his mission, he meets a devil whose appearance is that of a young boy.

(Source: Official Site)