King Kaiser reigns over Kaiser Castle, his crowned, bearded, and stout figure embodying classic regal authority. Charged with safeguarding the castle’s enchanted golden apples, he confronts a crisis when a witch’s golden bird steals the treasures. He commands his three sons to stand guard and unmask the thief, escalating tensions when the youngest, Hans, secures a glowing feather from the avian intruder. The king then dispatches his heirs on a perilous quest to capture the creature, propelling the tale’s pivotal mission.

His principled demeanor contrasts sharply with neighboring monarchs like Kanemacchi Castle’s tyrant, emphasizing his dedication to preserving his realm’s wealth and sovereignty. Though his decrees set the story’s trajectory—particularly through his sons’ charged pursuit—he remains a distant figure in later developments, his background and motives unchronicled beyond these decisive acts.