Jam Ojisan stands as the foundational creator within his universe. His inadvertent act of baking during a celestial event—a "star of life" striking dough in his oven—imbued the mixture with vitality, spontaneously generating the narrative's central heroic protagonist.

He manifests as an elderly figure marked by gray hair, prominent fluffy eyebrows, a mustache, and lighter red facial features than his creation. His consistent attire—a white chef's hat, shirt, pants, and apron paired with blueish-gray shoes—visibly affirms his baker's role.

His nature radiates profound kindness, warmth, and deep wisdom, positioning him as both mentor and paternal guide who encourages others toward their best potential. Expertise extends beyond baking into mechanical invention and repair, yielding specialized vehicles aiding heroic quests. This wisdom stems from extensive youthful travels, enriching a vast personal library.

Relationships define his presence:
- He shares a deeply affectionate, fatherly bond with the hero he created, having raised and nurtured him from inception.
- He offers guardianship and encouragement to other baked-goods-based characters like Melonpanna and Creampanda during their development, mirroring his care for the hero.
- With the antagonistic Rollpanna, he persistently seeks reconciliation, inviting her into the bakery community despite her villainous alignment, reflecting his enduring hope for redemption.
- He cohabits platonically with Batako in a close, family-like bond clarified as non-blood-related, sharing their home with the dog companion, Cheese.

Within the world's logic, both Jam Ojisan and Batako are explicitly identified as fairies, residing in a setting devoid of actual humans.

His background includes early conceptual depictions in original manga where he smoked a pipe, a detail omitted in animated adaptations and later manga revisions. Initially unnamed in 1973 picture books, he was referred to generically as "uncle" or "old man" before acquiring his current identity.