Haru is a handsome, tall, and slender young man with shaggy, two-toned snowy white hair with black roots that stick out in all directions. He has sharp yet slightly droopy dark brown eyes that give him a calm but cool appearance.

He wears the standard Kaibara High male uniform, consisting of a blue sweater (white during summer) with a yellow shirt underneath and a white collar and edges. Unlike most students, Haru wears his uniform unbuttoned and without a necktie, giving him a laid-back, rebellious look.

He accessorizes with chokers, spikes, small hoops or studs, and has a green tattoo on his right arm along with three piercings in each ear. Outside of school, influenced by Rin, Haru’s style leans toward punk fashion, favoring mostly black clothing, tight jeans, tank tops, chains, and white socks.

Haru has two contrasting personalities, “White” and “Black.” When he is in his “White” state, he is calm, kind, and laid-back, often speaking in a gentle and respectful tone. He typically maintains a straight-faced, composed demeanor and handles most situations with quiet maturity. However, when he switches to “Black Haru,” he becomes the complete opposite: violent, rude, foul-mouthed, loud, and short-tempered, often acting recklessly or teasingly perverted.

Despite his split personality, Haru is deeply loyal and caring toward those he loves, especially Yuki, Rin, Kisa, Hiro, and even Tohru. He often takes on an older brother role among the younger Zodiac members, offering them comfort and support when needed. While usually mature and observant, Haru has a playful side as well, shown when he whispered to Tohru in a way that embarrassed her and Yuki, though his intention was simply to help Yuki open up.

Haru’s “Black” side tends to surface when he is provoked or emotionally overwhelmed, such as when Kyo refuses to fight him or when Rin leaves him. It is revealed that “Black Haru” was born as a defense mechanism to cope with the ridicule and insults he endured as a child, allowing him to release his pent-up frustration while protecting his softer, more gentle self.

Ever since he was young, Haru had been ridiculed by the adults in the Sohma “inside” for being stupid, largely because of the story of how the Rat took advantage of the Ox to become first in the Zodiac. As a result, Haru subconsciously saw Yuki as an enemy and developed a deep-seated hatred toward him. Constantly being insulted and demeaned by the adults made Haru extremely irritable, eventually bringing out his black persona, which caused his parents great concern. They encouraged him to take up martial arts to relieve his stress. Although Haru enjoyed the practice and became friends with Kyo Sohma, it failed to ease his frustrations, as he still faced ridicule there.

Two years before the start of the series, Haru and Rin fell in love and consummated their relationship. Haru knew the potential consequences but pursued Rin nonetheless. When Akito discovered their relationship, Rin convinced Akito that she had seduced Haru. In retaliation, Akito pushed Rin from a second-story window, leaving her hospitalized. Haru, unaware of the full circumstances, was distressed. During this time, Haru grew increasingly concerned about Yuki’s suffering while living in the Sohma main house. He pleaded with Shigure Sohma to let Yuki live in his own home. Shigure agreed, on the condition that Haru address him as “sensei.”

• The nameHatsuharumeans “sprinkle, lively, vigorous” (溌) (hatsu) and “spring” (春) (haru).