Oskar's closest living family member, who provides comfort and guidance in the midst of his father's absence, living across the street and sharing a deep bond with him.

A man deeply affected by his past experiences in Dresden, Germany, who finds a connection to his grandson Oskar after a long absence, providing a link to the family's history.

A protective and grieving mother adjusting to life after her husband's death, maintaining trust in Oskar's independence and supporting him from a distance.

Oskar's intelligent and adventurous father, who dies in the 9/11 attacks, leaving behind an influential legacy in Oskar's life through their shared activities and quests.

An elderly neighbor who embarks on a journey with Oskar to find the lock to a mysterious key, reconnecting with the world after years of isolation.