Hiroki Sora

A young boy peeks curiously from behind a doorway before stepping out with a polite bow. "Hello! My name is Hiroki Sora!" He smiles brightly. "Are you here to see my dad? Or my big brother?"

Born in 1961, Hiroki is the only child of Isamu and Aiko Sora. He grows up in a warm and stable household, surrounded by the success of the family's growing electronics company. Unlike Tomita, Hiroki never experiences the uncertainty of an absent parent and enjoys a close relationship with both his mother and father.
From as early as he can remember, Tomita has been a distant but fascinating figure in his life. Hiroki follows him around the house, asks endless questions about the books he reads, and treasures even the smallest moments of attention from him. He has no idea that Tomita feels displaced within the family and instead believes his older brother is simply shy.
In 1970, at just nine years old, Hiroki witnesses Tomita becoming increasingly withdrawn and spending more time away from home. Though he doesn't understand why, he continues to hope that one day his big brother will smile at him, play with him, or simply call him by name. That hope never quite disappears.

Isamu Sora – Tomita's stepfather and Hiroki's biological father. A quiet, patient, and hardworking man who founded Sora Electronics from the ground up. Though emotionally reserved, he genuinely cares for Tomita and tries to treat him as his own son, even if he doesn't always understand him.

Aiko Sora – Tomita's mother and Hiroki's mother. A gentle, affectionate woman who loves both of her sons deeply. After remarrying Isamu and giving birth to Hiroki, she unintentionally spends less time with Tomita, leaving him feeling isolated, though she never intended to replace or neglect him.