Foolhardy police officer Brian Nightraider is dismissed from the force for a history of reckless behavior that ultimately resulted in his partner's death. While wallowing in self-pity, the disgraced officer receives a curious invitation from the United Nations Immigration Bureau Special Investigation Unit. He has been recruited to join the Marginal Service, a secret underground branch of the UN tasked with handling Borderlanders. Indistinguishable from humans, Borderlanders are aliens that peacefully coexist in society. But now, a Borderlander terrorist organization has emerged, manufacturing and distributing a potent drug called Confu. With the Borderlanders' ability to regenerate and blend in as humans, uncovering the drug-trafficking ring will be no easy undertaking. However, the ragtag group at the Marginal Service are not one to back down from a challenge—even as their work exposes some unexpected figures as Borderlanders.

After uncovering the truth behind their father's untimely death, life for the four Shimogamo brothers returns to relative peace with each trying to live up to their father's greatness in their own way. For the eldest, Yaichirou, who aims to become the next Trick Magister and leader of the tanuki society, it starts with reinstating the popular shogi tournament. For Yajirou, it is restoring his former shapeshifting abilities, whilst little Yashirou is content with continuing his work at the family’s factory. But for the third son, Yasaburou, it simply means embracing the fool's blood he inherited from his father and living a carefree but interesting life. This, of course, includes hunting for the mysterious and elusive snake-like creature known as a tsuchinoko, and causing ripples of trouble at every turn. However, these ripples threaten to turn into waves with the return of Nidaime, the estranged son of the brothers' tengu teacher, Professor Akadama. Nidaime bears a grudge against not only his father, but his father's apprentice Benten as well. His loyalties suddenly brought into question, Yasaburou must use his tanuki wit to appease all sides without getting caught in the crossfire, before the delicate balance between human, tengu, and tanuki is overthrown and all hell breaks loose.

Within the horse-racing world, the horse girls of Team Spica have been gaining popularity as they continue to rack up victories. The one receiving the most attention in the group is Toukai Teiou, known for her cheerful personality and exceptional running skills. Teiou aims to become an undefeated Triple Crown horse girl by winning all three G1 races consecutively, a feat that has not been accomplished since the legendary Symbolic Rudolf managed to do so many years ago. On her path to obtaining the Triple Crown, Teiou is met with many challenges, encountering both old and new rivals. Amidst her fierce rivalries, however, Teiou is soon confronted with decisions that will leave a huge impact on her very own racing career.

Famous racehorses that have left behind worthy legacies, unique as they can be, are reincarnated as horse girls in a parallel world. In this life, they start their journey anew as they continue to race and perhaps relive the success they once lived through. Aspiring to become the best racehorse in Japan, a horse girl named Special Week moves to Tokyo to enroll in the Tracen Academy—an institution that nurtures horse girls like her to become better racers. There, Special Week witnesses the sophisticated running style of Silence Suzuka and is inspired to become a racer like her. Shortly after, Special Week finds herself recruited into Silence Suzuka's team, Spica. From there, she begins her path to the top—one lap at a time.