Haru Tennōji is one of the two central protagonists in the story and the co-founder of the company Trillion Game. He is a young man who unabashedly proclaims himself to be the worlds most selfish person, a title he wears as a badge of honor while pursuing his singular ambition to earn one trillion dollars. His background reveals a sharp and driven individual who was once an employee at Dragon Bank Enterprises, a massive financial corporation. He ultimately chose to leave that secure position when the company refused to hire his talented but socially awkward friend, Gaku, demonstrating that his loyalty to his partner outweighs the stability of a traditional career path.

Personality is where Haru truly distinguishes himself. He is gifted with extraordinarily high communication skills, a sharp intellect, and notable physical strength. He is a master negotiator and a natural-born salesman, possessing a silver tongue that allows him to lie, bluff, and persuade with effortless charisma. He thinks and responds with unbelievable speed, and he possesses an unmatched will to never give up, willing to use any means necessary to achieve his goals. While he can appear amoral and recklessly ambitious, this is tempered by a fierce protective instinct. He responds with ruthless wrath when someone under his care is wronged, a trait that often drives his most decisive actions, such as quitting Dragon Bank after seeing Gaku relegated to a window-washing job instead of the programming position he deserved.

Within the narrative, Haru serves as the visionary and driving force behind Trillion Game. He acts as the companys liaison, its head of sales, and the primary business decision-maker. His role is to be the charismatic frontman who opens doors and secures deals, while his partner Gaku provides the technical genius behind the scenes. Harus core motivation is not merely wealth for comforts sake, but the sheer thrill of the game and the challenge of conquering the business world. He dreams of building a trillion-dollar enterprise from the ground up, and he is relentless in his pursuit of this goal, often concocting elaborate schemes to outmaneuver larger, more established rivals.

The most significant relationship in Harus life is with his partner, Gaku. Where Haru is bold and outgoing, Gaku is reclusive and timid. Haru recognized Gakus latent programming talent when he saved him from being bullied, and he has supported him ever since, valuing his engineering ability above all else. This partnership is a classic study in contrasts, with Haru providing the social firepower and Gaku providing the technical foundation. Haru also has a complex relationship with Kirika Kokuryū, the brilliant and arrogant heiress to the Dragon Bank fortune. She becomes obsessed with Haru and Gakus potential, and while she often tries to bring them under her control, she also finds their independence entertaining and occasionally assists them. Haru is also the one who recruits the companys first investor, Kazuki Kedōin, and its president, Rinrin Takahashi, using his charm to build the team around him.

While Haru appears supremely confident from the start, the story implies a degree of development through his interactions with Gaku. His ambitious schemes force Gaku to grow from a passive follower into a more assertive individual, and in turn, Gakus moral compass sometimes causes Haru to reflect on his own methods. Harus notable abilities extend beyond his social genius. He is multilingual, fluent in languages including English, Chinese, and French, which aids his global ambitions. He is also physically capable and has a peculiar specialty for cooking a large-portion spicy fried rice. In the present-day timeline of the story, which is told as a flashback from Gakus perspective, Haru is notably absent, and his whereabouts remain a mystery that looms over the narrative.