Kaito Irie, an unremarkable young man without any real hobbies, is killed due to a careless mistake by a goddess. As compensation for his untimely death, she offers him a chance at a new life in a fantasy world. But rather than a single gift, he is granted three specific passions to guide him: Collection, Animal Ears, and Laser Beams. Armed with this god-given power to fire a beam strong enough to destroy any foe yet precise enough to function as any tool, Kaito is reborn and sets out as an adventurer seeking riches and glory.

The protagonist, Kaito, was a bored salaryman in his previous life, but in this new world he becomes a peerlessly powerful warrior. He is joined by his animal-eared companions, Oltea and Frieze, as he tirelessly helps the oppressed half-animal, half-human hybrids that inhabit the land. While his actions bring him the title of Sword Saint and a comfortable life watching over the kingdom, his motivations are ambiguous—he acts out of genuine kindness, but also out of a strong desire to get closer to their irresistibly adorable ears.

The story is set in a standard fantasy realm of swords and magic, but one where beastfolk are often downtrodden and disgraced. The central conflict of the first volume revolves around Kaito using his versatile death beam to smite monsters and villains while indulging his newfound passion. The narrative's notable arcs include his rise from a reincarnated nobody to a celebrated Sword Saint. In the second volume, the peace in the Royal Capital is threatened by the arrival of Tigaro, a tiger-eared girl living in disgrace after standing up for her oppressed friends. Simultaneously, the adventurer’s guild warns of a great forthcoming surge of monsters known as the Stampede, a threat that surpasses even the demon army of a villain named Vlad and appears to be mysteriously linked to Tigaro’s past.