TV-Series
Description
Kōta Oyamada, an orphaned high school student, moves to the city after living with his grandfather in the countryside. His deceased parents' details remain unspecified. This rural background initially shapes him as innocent, mild-mannered, shy, passive, and indecisive. He is notably short for his age with brown hair and silver (or green, per some sources) eyes, causing others to mistake him for younger. A childhood near-drowning incident instilled a lasting fear of swimming.

On his first day at Kunpō High School, second-year kitsune (fox spirit) Chizuru Minamoto immediately pursues a romantic relationship with him. Her frequent public displays of affection embarrass Kōta, earning him nicknames like "Great Erotic King" or "beast" among peers. Though initially reluctant toward intimacy—partly due to his grandfather's advice against early relationships—Kōta develops a genuine emotional bond with Chizuru. This profound connection allows them to supernaturally fuse into a single entity, temporarily transforming Kōta into a black-furred, five-tailed fox spirit. Chizuru's brother Tayura confirms the fusion stems from their deep emotional link. In the manga, this links to Chizuru's status as a nine-tailed fox with unlimited power; Kōta inherits a portion tied to the Eight Dragons.

Kōta's life grows more complex with Nozomu Ezomori, a 200-year-old wolf spirit who transfers into his class and develops strong romantic feelings for him, becoming Chizuru's rival. Kōta shows care and concern for both. His kindness cements Nozomu's devotion when he helps her during a confrontation with a vendor. Despite rivalry, Nozomu occasionally assists Kōta and Chizuru in conflicts.

Kōta's relationships extend beyond romance. His dynamic with Tayura evolves from Tayura's initial jealousy (rooted in a sister complex) to a supportive, brotherly bond. He befriends class representative Akane Asahina, who disapproves of Chizuru's behavior but remains amicable with him. Kōta also earns approval from Tamamo, Chizuru's powerful kitsune matriarch foster mother, after enduring supernatural trials testing his loyalty and love. These include resisting a magical wine’s influence that nearly causes him to betray Chizuru with Nozomu.

Throughout conflicts—facing spirits like Saku (Nozomu's brother, who places a life-threatening seal on Kōta) and Omi Kiriyama (a sickle weasel spirit)—Kōta transitions from passivity to actively protecting others, notably shielding Chizuru from harm. His resolve culminates in openly declaring his love for her at their first-meeting bridge, leading to marriage.

Later, Kōta and Chizuru have a biological daughter and adopt twin spirit hunters Ren and Ai Nanao, who call them parents. He maintains responsibility for his extended family, including Nozomu, who remains a devoted lover alongside Chizuru. Kōta’s childhood included three pets: a dog (Pochi), a cat (Mike), and a goldfish (Yarkovsky). His name’s etymology reflects agricultural terms: "Kōta" combines "till/plow" (耕) and "thick/big/great" (太), while "Oyamada" means "small mountain field" (小山田).