Undefeated Bahamut Chronicle

10 years after the event, humans at the royal capital gather wealth, the demons are enslaved to assist with the capital's revival, and the gods lose their power due to a decrease in religious piety. The world is thrown off balance as humans, gods, and demons hold their own ideas of justice.

Mistarcia is a magical world where humans, gods, and demons mingle together. In the past, the black-and-silver winged Bahamut has threatened to destroy the land, but humans, gods, and demons overcame their differences to fight together and seal its power. The key to that seal was split in two, one half given to the gods and the other to demons, so that they would never be united and Bahamut never released. Now, two thousand years later, the world is in an era of peace—until the day a human woman steals the gods' half of the key.

Hida Kizuna possesses the HHG (Heart Hybrid Gear) ability, but it is not strong enough to make him particularly important. His older sister calls him to transfer to a strategic defense school, where many of the students (many of which are large-breasted girls) use their HHG abilities to fight invaders from another world while wearing extremely skimpy pilot outfits. Kizuna's fighting ability doesn't measure up, but his sister has another plan; getting the girls to have erotic experiences with Kizuna, so that it will allow them to replenish their energy or power-up. It looks like his new school life is going to be full of embarrassment!

Learning to ride and tame dragons comes easy to most students at Ansarivan Dragonar Academy—except for first-year student Ash Blake, who is known by his fellow classmates as the "number one problem child." Poor Ash is the laughing stock at school because, despite his unfashionably large star-shaped brand that marks him as a future dragon master, he has nothing to show for it. His dragon has never appeared. Until now, that is. One fateful day, Ash's dragon awakes in full glory, but appears different than any dragon ever seen before—in the form of a beautiful girl! What's worse, Ash soon discovers that this new dragon has attitude to spare, as she promptly informs him that she is the master, and he, the servant. Ash's problems with dragon riding have only just begun.