TV-Series
Description
Haruhi Teramitsu is one half of the Teramitsu twins, being the younger brother of Yuduki Teramitsu. He is of mixed heritage, born to a British father and a Japanese mother. Haruhi has blonde hair that reaches his neck and blue eyes, with physical traits that mirror his twin brother, including a mole on the opposite side of his neck. He stands 173cm tall and weighs 58kg, with an April 9th birthday and O blood type. His representative animal is the rabbit.

Haruhi has an extroverted and attention-seeking personality that stands in stark contrast to his twin. He likes to showcase his accomplishments and can talk about them endlessly when praised. He has a tendency to put too much effort into tasks he is given. Under extreme stress, Haruhi reverts to speaking English. Despite his cheerful and sometimes self-centered exterior, he possesses deep loyalty, particularly toward his brother. He has a well-noted fascination with the mascot brand Oshiriz, owning a cushion of it on his bed. He also has a habit of evaluating people's buttocks upon first meeting them, and maintains that his brother has the best. He enjoys fashion, shopping, and watching stage comedies during his free time.

Haruhi's background is marked by significant childhood hardship. He was often ill and could not go out much, which left his social world largely confined to his twin brother, though he has admitted he did not feel lonely because Yuduki was always by his side. Their mother suffered from a chronic illness that required hospitalization before the twins were four years old, and she passed away after several years without ever returning home. Following their mother's hospitalization, their father gradually stopped coming home and eventually quit his job and disappeared. After their mother's death and the subsequent passing of their grandmother, their Japanese grandfather took them to live in Japan. When their grandfather also passed away, the twins ended up in an orphanage where they formed a close bond with the director, whom they affectionately call "grandma".

Motivation and role in the story center on his identity as an idol. After three years of joint training, Haruhi debuted as a member of the unit KiLLER KiNG alongside his brother Yuduki, Akane Fudo, and Miroku Shingari. While he was initially disappointed at not being chosen for B-PROJECT's debut, he committed himself fully to his unit.

Key relationships define much of his character arc. His bond with his twin brother Yuduki is the most significant and complex. Haruhi relies heavily on Yuduki for emotional support due to the dependency formed during his childhood illnesses. He is fiercely protective of his brother, to the point of historically diverting romantic interest from Yuduki to himself as a shielding tactic, a behavior that re-emerges when a female celebrity pursues Yuduki. This overprotectiveness sometimes creates friction, as Yuduki seeks to establish his own identity beyond being one of the twins.

Haruhi shares a mentor-like dynamic with Goshi Kaneshiro, and together with Yuduki they are known as the Returnee Trio due to their experience living abroad. Haruhi expresses his admiration for Goshi by cooking his favorite curry, borrowing his clothes, and dreaming of going out for drinks with him when he comes of legal age.

He also develops a meaningful relationship with Tsubasa Sumisora, B-PROJECT's A&R staff member. His interactions with her shift from lighthearted flirtation to genuine connection and reliance, particularly during conflicts with his brother.

Haruhi shows notable character development throughout the series. An outdoor camping trip leads to an argument with Yuduki after Haruhi neglects to apply sunscreen, which prompts him to express his lifelong gratitude for his brother's care and his own desire to protect Yuduki in return. A significant turning point occurs in Ryusei Fantasia when his protective instincts clash with Yuduki's desire for autonomy. When Haruhi discovers that Yuduki has confided details of their orphanage past to Tsubasa, he reacts with anger, viewing such matters as private. Tsubasa's intervention helps him understand his brother's perspective, prompting him to reassess his approach to their relationship. This evolution extends to his feelings for Tsubasa, which develop from superficial advances into sincere interest.