With Anya Forger successfully enrolled at the renowned Eden Academy, Operation Strix advances to its second phase. To investigate Ostanian politician Donovan Desmond, Anya must either befriend his son Damian or collect eight Stella Stars to become an Imperial Scholar. Fortunately, Anya has already acquired her first star. In celebration, her adoptive father, Loid, decides to fulfill her wish to adopt a dog. During their canine search, Loid receives new orders from his superiors, who have found that a band of Berlint University students is plotting to assassinate Westalis' Minister Brantz using bombs worn by trained dogs. While Loid tries to stop their plans, Anya stumbles upon the terrorists' base of operations. There, she befriends a kindhearted, clairvoyant dog who the family later names Bond. Although the Forgers continue to lead their individual lives in secrecy, the family—with a new fluffy addition—remains united through all of the unusual obstacles thrown their way.

Among all the beasts that roam the world, there are unique types of "ultimate species" that harbor immense strength and magical prowess considered to be at the top of the power scale. As such, many humans covet their abilities, leading some of these species to the brink of extinction. As a beast tamer, Rein Shroud can employ the assistance of various animals for many tasks, such as reconnaissance and logistics. By virtue of his ability, he joins a party led by the vile and manipulative hero Arios Orlando, only to be banished after six months due to his uselessness as a non-combative class. However, unbeknownst to the team that cast him away, Rein is an exception among beast tamers. His potential becomes apparent when he meets Kanade—a cat spirit who is also one of the ultimate species—and is able to form a contract with her. With Kanade by his side, Rein sets out on his journey as an adventurer, steadily rising up the ranks and meeting more ultimate species along the way.

During the summer holidays, energetic Hana Uzaki spent most of her time accompanying her lonesome upperclassman, Shinichi Sakurai. Now that school has resumed, Uzaki's teasing continues to ramp up, much to Sakurai's constant annoyance. Nevertheless, no amount of ridicule can damage the pair's relationship—which only seems to be getting better as their college days fly by!

College student Yuuhi Amamiya's monotonous life is turned upside down with the appearance of Sir Noi Crezant, a talking lizard claiming to be a knight of justice. Crezant elaborates that the world is in peril—threatened by the mage Animus who wishes to annihilate it with his Biscuit Hammer, an enormous structure suspended in Earth's orbit. As the newly appointed Lizard Knight, Yuuhi must fight alongside other Beast Knights to protect the princess and save the planet from destruction. Unimpressed by the prospect of risking his life, Yuuhi continues his day as usual—until a golem created by Animus suddenly confronts him. Yuuhi is instantly overpowered, but his neighbor, Princess Samidare Asahina, luckily rescues him. To his surprise, Samidare's intention starkly differs from Crezant's; instead of saving the world, she aims to destroy it with her own hands. Captivated by her firm ambition, Yuuhi resolves to become stronger and help Samidare realize her goal. As the pair continues to fight against Animus' golems, Yuuhi finds himself gradually gaining an interest in life—but the chains of his past trauma may restrain him from progressing further.