Tsutomu Amai is the president of 283 Production, a small entertainment agency operating from an office above ground-floor shops like pet stores, laundries, and bookstores in a three-story corner building near Tokyo's Seijo Sakuragaoka Station.

He maintains a stern, serious, and often harsh professional demeanor. This contrasts sharply with his deeply compassionate core, particularly towards the idols he manages. He experiences profound emotional reactions to their successes, frequently moved to tears when they achieve milestones, though he consistently denies or conceals this vulnerability. The Producer at the agency has noted his physical appearance possesses a dandy-like quality.

His background includes producing the legendary idol Nami Yakumo, whose legacy significantly influences Nichika's storyline. He shared a close friendship with Hazuki and their now-deceased father. Presently, Hazuki Nanakusa works part-time as his secretary at 283 Production, assisting both Tsutomu and the Producer. In his leadership role, Tsutomu sets strategic directions for the agency, such as instructing the Producer to prepare all idols for major events like the Wonder Idol Nova Grand Prix (WING).