Masao Inuyama leads the Inuyama family as its head and father to Rumi Inuyama. He steers a prominent Japanese IT company positioned near the industry's peak. Yet, despite this professional stature, severe financial difficulties plague his family. Substantial loans, taken to secure their upscale Roppongi Hills residence after relocating from Kyushu, threaten the company with bankruptcy.

The family's spending habits further compound these financial woes, generating considerable stress for Masao as he struggles to manage escalating expenses and maintain household stability. Throughout these mounting pressures, he remains steadfastly supportive of his family, dedicated to their well-being.

Within this family structure, Masao is married to Yoko Inuyama. Their extended household also includes Rumi's grandparents, Toranosuke and Kaoruko Inuyama.