Hatsuharu "Haru" Soma, plagued by a curse that transforms him into an ox if embraced by the opposite sex or overwhelmed by stress, sports stark two-toned hair—white strands cascading over black roots—and adorns punk-inspired attire accented by handmade jewelry. He embodies a dual nature: the serene "White Haru" contrasts his fiery, confrontational "Black Haru," a defense mechanism forged through childhood taunts about the ox’s perceived dimwittedness in zodiac lore.

Initially resentful toward Yuki Sohma (the Rat) for the zodiac legend’s betrayal, Haru’s perspective shifted when Yuki helped him reclaim self-worth, sparking unwavering loyalty and deep affection. This bond drove Haru to orchestrate Yuki’s escape to Shigure’s house, shielding him from Akito’s cruelty. He champions younger zodiac members like Kisa and Hiro, aiding them through crises such as locating Kisa after she fled bullying.

Haru’s clandestine romance with Isuzu "Rin" Sohma ignited in their teens. Discovered by Akito, Rin endured brutal punishment, prompting her to sever ties to protect him. Learning the truth from Hiro, Haru confronted Akito while grappling with guilt over Rin’s suffering. Despite estrangement, they reconciled, with Haru pledging steadfast emotional support. Their journey culminated in marriage and twins, Sora and Riku, in the sequel.

When the zodiac curse dissolved alongside other bonds, Haru embraced the change, redirecting his focus toward a future with Rin. He preserves close bonds with former zodiac peers, reflecting on their collective resilience.

Notable quirks include being notoriously directionally challenged, sparking comedic mishaps, and training in martial arts to channel his temper. His dialogue mixes deadpan wit with incisive observations, often mediating tensions between figures like Kyo and Yuki.