Taking place at Winford Academy located in an old town called Helen's Hill, the story is all about knights and the sport of jousting. At this school, students learn how to become knights, ride horses and joust properly. The main character is a young man named Takahiro Mizuno who was training to become a knight and jouster but after suffering an injury he dropped out of the knight program and joined the begleiter (assistant) program instead. Due to his animal handling skills and former experience as a jouster, this makes him a hot commodity. Multiple beautiful girls in the school want him to become their personal begleiter, though Takahiro always refuses their offers. One day a bizarre accident causes his friend, Mio Kisaski, to be challenged to a jousting duel despite her not actually being a knight. Takahiro agrees to become her temporary begleiter, but that ends up only being the beginning of their partnership as she enrolls in the annual tournament.

Her name is Mary Saotome—she is brazen, insolent, and defiant, yet highly intelligent. Upon transferring to Hyakkaou Private Academy, where a student's worth is determined by their wits through gambling, she seizes a glorious win against a classmate and immediately captures the attention of the devious student council members. With the bottom of Hyakkaou's rigorous hierarchy determined by least gambling winnings, the future for Tsuzura Hanatemari looks grim. As Tsuzura's childhood friend, Mary resolves to rise through the ranks and secure enough money to free Tsuzura from the shackles of the unjust system. Mary's perseverance and refusal to lose drive her to surpass and humiliate even the strongest opponents, but certain student council members seem to have greater plans for her.

Under the tutelage of the great demon warlock Romberg, Ike grew up with knowledge regarding an ancient advanced civilization that once ruled the land. Coupled with his innate talent in magical arts, this upbringing allows Ike to quickly rise in the Demon Lord's army ranks, leading his brigade to consecutive victories against humans. However, Ike has a secret—he is a human himself. Despite knowing all too well the consequences if this information is ever to leak, Ike is willing to face such immense danger to achieve his goal: find a way for humans and demons to coexist and stop the war that has been carried on for far too long.

Having lost her mother at a young age, Misha Takanashi, a second grader who is Russian now lives with her Japanese step-father. Tsubame Kamoi, formerly a Japan Air Self-Defense Force, JASDF officer, comes to the Takanashi household as a housekeeper. This is a home comedy where Kamoi, a hardcore lolicon, attempts to get near Misha as she tries to fight against her.