Rika Kinugawa

"Hundred"—that is the only weapon that can oppose the mysterious life form "Savage" from visiting the earth. The protagonist, Kisaragi Hayato, aims to become a Martial Arts Master using this Hundred. He managed to get into the battleship university Little Garden. However— "I wanted to see you, Hayato!!!" "H-How do you know my name?" Around the roommate, Emil Crossford, who somehow knows him well (?), Hayato gets an uneasy feeling. What's more, just after the entrance ceremony, he gets asked for a duel by the campus' strongest martial arts master "Queen" Claire Harvey...!? The ultimate academy battle begins here!

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—apparently having erotic experiences with Kizuna will allow the girls to replenish their energy or power-up. It looks like his new school life is going to be full of embarrassment.

Avid bookworm and college student Motosu Urano ends up dying in an unforeseen accident. This came right after the news that she would finally be able to work as a librarian as she had always dreamed of. When she regained consciousness, she was reborn as Main, the daughter of a poor soldier. She was in the town of Ehrenfest, which had a harsh class system. But as long as she had books, she didn't really need anything else. However, books were scarce and belonged only to the nobles. But that doesn't stop her, so she makes a decision... "If there aren't any books, I'll just create some."

Fuutarou Uesugi is a poor, antisocial ace student who one day meets the rich transfer student Itsuki Nakano. They argue but when Uesugi realizes he is to be her tutor, he tries to get on better terms. While trying to do so he meets four other girls.