"Monster no Konkatsuya-san" centers on the life of a matchmaking consultant who specializes in arranging marriages for monsters. The protagonist, a human named Tetsuo, works for a unique agency that caters to the romantic needs of supernatural beings. His job involves understanding the diverse and often complex requirements of his monstrous clients, ranging from vampires and werewolves to ghosts and demons. Tetsuo’s role is to navigate the intricacies of their cultures, preferences, and societal expectations to find them compatible partners.

The narrative explores the challenges Tetsuo faces in his profession, such as overcoming cultural misunderstandings, addressing the unique needs of his clients, and dealing with the occasional chaos that arises from their supernatural traits. Each chapter typically focuses on a different monster client, showcasing their individual stories and the hurdles they must overcome to find love. The series blends humor, romance, and lighthearted drama, often highlighting the absurdity and charm of interspecies relationships.

Key characters include Tetsuo, whose dedication and empathy make him a skilled matchmaker despite his human limitations, and his colleagues at the agency, who provide support and comic relief. The monsters themselves are portrayed with distinct personalities and quirks, making each matchmaking scenario unique. The series also touches on themes of acceptance, diversity, and the universal desire for companionship, regardless of species or origin. Through its episodic structure, "Monster no Konkatsuya-san" offers a whimsical yet heartfelt exploration of love in a world where humans and monsters coexist.