Although traumatized by witnessing the murder of his parents by one of the Choushuu, Ichimura Tetsunosuke's thirst for revenge lead him to desire strength. At the age of 15, Tetsunosuke approached the Shinsengumi, wanting to become one of its members. However, Tetsunosuke lacked the skill, mind and will to emotionlessly cut down whoever threatened peace and the Shinsengumi. Even with the support of his brother Tatsunosuke and his newfound friends of the Shinsengumi, little did Tetsunosuke know the blood and pain he would have to face being part of this historical group.

Thanks to the Sibyl System, the mental states of society can now be measured on a numerical scale. Using these "crime coefficients," a culprit can be apprehended before they ever commit a crime. But is it a perfect system? For Inspectors Kei Mikhail Ignatov and Arata Shindou, that remains to be seen, as their career with the Public Safety Bureau's Crime Investigation Department has only just begun. Shindou and Ignatov are assigned to investigate the crash of a ship carrying immigrants, but they begin to suspect that it was no mere accident. Meanwhile, a mysterious group called Bifrost is observing them from the shadows, but they aren't the only ones who have taken an interest in the two new Inspectors...

Yamato Akitsuki travels to Tokyo alone to study in one of the high schools located within the area. He lives in with his aunt who operates a public bath solely for the ladies in the local district and begins his normal high-school life. One day, he chances upon a girl in school and is immediately mesmerized by her beauty. He is shocked when he realizes later that the girl, Suzuka, is actually living next door to him. From then on, Yamato's ordinary life begins to change little by little.

Ikta Solork is a carefree young man who only wants two things in life: a woman on his arm and a place to nap. Unfortunately, his peaceful life is destroyed when war breaks out between the Katjvarna Empire and the neighboring Republic of Kioka. Ikta and his childhood friend, Yatorishino Igsem, join the army as military officers, where they meet the infantryman Matthew Tetojirichi, the sniper Torway Remion, and the medic Haroma Becker on a boat heading for the military exam site. However, after a rogue storm sinks their vessel, the five of them end up in enemy territory near a military outpost. There, they discover that the heir to the Katjvarnan throne, Princess Chamille Kitora Katjvanmaninik, has been taken hostage. The five are able to rescue her, and as a reward, each one of them is granted the title of Imperial Knight—one of the highest honors a soldier can receive. It seems that Ikta will have to put his dream of tranquility on hold, as he must now become the hero he never wanted to be.