Isami Aldini, fraternal twin of Takumi Aldini, belongs to Tōtsuki Culinary Academy's 92nd Generation. Born in Italy to a Japanese-Italian family, he worked alongside Takumi at their family's Trattoria Aldini since childhood. Though generally outperforming his brother in most domains, Isami developed cooking-related insecurities when patrons specifically requested Takumi's dishes. After revising Takumi's recipe and receiving paternal criticism for dulling its flavors, Takumi consoled him. They vowed to improve jointly and elevate Trattoria Aldini to Italy's pinnacle. Their uncle later recommended Tōtsuki for skill refinement, with Isami persuading Takumi to enroll. Isami's physique undergoes dramatic seasonal shifts. Initially obese with spiky brownish-black backward-combed hair, cartoonishly small eyes, and prominent shark-like teeth, he shed weight during summer due to heat and academic pressure, becoming slender and taller than Takumi. This transformation revealed his strong resemblance to his brother, with sharper, more open eyes and less noticeable teeth. He typically regained weight in winter but maintained his slim build after his second year began due to rigorous schedules. Personality contrasts with Takumi's fiery nature; Isami exhibits calm, jovial, and peaceful tendencies, often laughing at Takumi's brashness or teasing him during competitions. Beneath his cheerful exterior lies deep-seated insecurity about his culinary skills. He remains fiercely loyal to Takumi, resolving to improve after Takumi's Autumn Election quarterfinal defeat to prevent future failures. His affable nature fosters friendships with peers like Sōma Yukihira and Megumi Tadokoro. At Tōtsuki, Isami partnered with Takumi during the Friendship and Rapport Training Camp, preparing Aigamo Grilled Duck with Spices using synchronized mezzaluna techniques. He later competed solo in the Autumn Election preliminaries' Block B, creating a Curry Bread Calzone that fused Japanese curry and Italian calzone—tomato-based curry encased in pizza dough. Judges praised its innovation, momentarily overshadowing Takumi's subsequent entry, though Takumi scored higher overall. This event marked Isami's growing culinary independence. Culinarily, Isami specializes in Italian cuisine with Japanese influences, demonstrating mezzaluna proficiency for rapid mincing and adept knife skills. He frequently collaborates with Takumi as sous-chef but also crafts individual dishes like his Autumn Election calzone. He later assisted Sōma with noodle preparation during the Moon Banquet Festival. By third year, Isami secured an Elite Ten Council seat. Post-graduation, he returned with Takumi to manage Trattoria Aldini in Italy, fulfilling their childhood pledge.