Five years ago, Musashi made a promise with his friend Kojirou Kanemaki that once they grew up, they would become samurai, form a league, and go on demon-slaying quests. But since then, things have changed. With demons now being praised and worshipped by society, the samurai are shunned and disgraced. Afraid of revealing his dream of becoming a samurai, Musashi blends into the town's dogma by becoming a miner while secretly polishing his swordsmanship. Meanwhile, despite being a direct descendant of a samurai, Kojirou gives up on his promise to his old friend. However, after saving Musashi from a near-death experience, his perspective shifts. Although still conflicted, Kojirou embarks on a journey with Musashi in the hopes of figuring out his true feelings. Fighting against all odds, the duo dives headfirst into the unknown world of beast-slaying, not knowing what life has in store for them. Now astride iron horses, the fifteen-year-old heroes plan to restore the tarnished reputation of the samurai and purge the world of demons.

The silent and stoic Chateau Dankworth is a bounty hunter. Her target: Son Ryang-ha, a notorious killer known for killing 18 high-class officials in a single night. To this day, his murders remain swift, efficient, and bloody. However, after Son Ryang-ha overpowers Chateau in their first encounter, he reveals his own intentions: he too is after her, aiming for her heart. Son Ryang-ha's attempts to catch her eye are quite unique, to say the least. He offers gifts to her in the form of her current targets, tied up and battered, and will do anything to spend more time together. Reluctantly, Chateau goes along with this act, and so begins the cat-and-mouse game of love between two killers. [Written by MAL Rewrite]

Female police officer Kawai had enough of a career she wasn't even that into and was about to hand in her registration, when the unthinkable happened—she met the new, female director of her station! And after spending a little time with this gorgeous role model, Kawai realizes that maybe she isn't quite done being an officer after all.

Kazenone City, it is a city that made people feel nostalgic and wonder. It was also the home country of Okano Makoto and his little sister, Hinata. They came back this town in order to look for their mother who had disappeared suddenly. Their friends and childhood friends welcomed their return. Makoto began to notice something important through the encounter with them. With the tone of a harmonica, and with their thoughts in their hearts, the fantastic tale began in this mysterious town.