Lux, a former prince of an empire named Arcadia that was overthrown via a rebellion five years earlier, accidentally trespasses in a female dormitory's bathing area, sees the kingdom's new princess Lisesharte naked, incurring her wrath. Lisesharte then challenges Lux to a Drag-Ride duel. Drag-Rides are ancient armored mechanical weapons that have been excavated from ruins all around the world. Lux used to be called the strongest Drag-Knight, but now he's known as the "undefeated weakest" Drag-Knight because he will absolutely not attack in battle. After his duel with Lisesharte, Lux ends up attending the female-only academy that trains royals to be Drag-Knights. (Source: ANN)

Though he grew up as an orphan, Nio Chirinu finds a place to belong: being a waiter at his adoptive grandmother's restaurant. But this peace does not last long; Nio and his sister Iroha are used as bait to arrest child abductors by Toshizou Hijikata and Souji Okita—two members of an infamous ronin group called Miburo. After the ordeal, Toshizou proposes that Nio join the ranks of Miburo and protect the people of Kyoto. Frustrated by his own weakness, Nio trains to match the swordsmanship of his new comrades. Even so, he struggles to be accepted by Tarou Tanaka and Hajime Saitou, the other Miburo members of his age. Determined to befriend them, Nio must discover his own sense of justice and become strong enough to prevail against all his enemies.

When Isaku Senagaki was five years old, the death of her parents left her to be raised by her yakuza boss grandfather, Tasuke. Now preparing to enter high school, Isaku is determined to start fresh with an honest attempt at having a normal high school experience. All she wants is to be able to make friends and find love without being defined by her connection to the yakuza. But Isaku's dreams are thwarted when her overprotective caretaker, 26-year-old Keiya Utou, takes it upon himself to enroll in Isaku's school by bribing the school administration. While Isaku yearns for a reciprocated love, she is trapped in a one-sided infatuation with Keiya, who only sees her as the boss's granddaughter he helped raise. Her longing for a normal life becomes a constant battle, and breaking free from her heart's grip is far more challenging than it sounds, as Keiya's overprotectiveness and disregard for her boundaries make it almost impossible to move on.

Mitsuha Yamano could not have had it worse. After failing to enter her university of choice and losing her entire family in an accident, she finds herself plummeting off a cliff due to an especially fragile guardrail. Through what seems to be the only bit of the fortune left in her life, Mitsuha's firm unwillingness to die allows her to be transported to another world, where she ends up surviving. In this foreign land, Mitsuha wanders around for days before collapsing from exhaustion and being rescued by a little girl named Colette. Not long after, she finds herself in yet another life-threatening situation, and her indomitable will shines once more, granting her an audience with a divine cosmic being. The entity reveals to Mitsuha that she has acquired not only superhuman regeneration but also the ability to transport between worlds at will. Armed with this new information, Mitsuha brainstorms ways to utilize her newfound power to its full potential. Realizing that she can take goods from Earth and resell them to the other world at a higher price, she resolves to save up eighty thousand gold coins to be able to retire comfortably.