Okamura Kouji is the father of Aya Okamura and husband to Minako Okamura. He lives alone in the family home while his wife works overseas as a doctor, caring for their elderly pet cat, Mii-san. Kouji originally acquired Mii-san as a kitten to comfort his young daughter Aya during Minako's initial absence.

After Aya moves out for work, Kouji feels lonely and reaches out to maintain contact, inviting her for dinner. Aya declines, falsely citing work commitments. Kouji's life settles into quiet solitude centered on caring for the aging Mii-san.

When Mii-san passes away, Kouji contacts Aya to inform her. This prompts Aya to visit her father. During this meeting, they share a meal, beginning to mend their strained relationship.

Subsequently, Kouji adopts a new kitten. When Aya visits again to see the new kitten, her mother Minako unexpectedly returns home. This reunites the family, restoring a sense of closeness and happiness.

Kouji is characterized by his reserved demeanor and underlying care for his family. His actions reflect quiet dedication, from providing companionship to his daughter through Mii-san during her childhood to reaching out during his own isolation. His experience illustrates themes of familial separation, aging, and reconciliation, culminating in the family's reunion following shared loss and renewal.