Movie
Description
Kiyui, a young boy living at Belchero Orphanage, is markedly younger than peers such as Riko, Nat, and Shiggy. He has short blond hair with a distinctive curled strand on his forehead and blue, often half-closed eyes. As a Bell-ranked Cave Raider apprentice, he wears the orphanage’s standard white sailor-collar shirt with brown shorts or baggy pants, along with a neck bell signifying his rank.

His friendly, good-natured personality is accompanied by an awkward speech pattern reflective of his age. Older orphans provide significant supervision and affectionately treat him as a younger sibling. He displays emotional sensitivity, crying easily during conflicts like Riko and Nat’s argument over her Abyss departure, where Reg comforts him. His development includes gradually handling responsibilities like delivering letters and shopping alone for short distances.

Before the main journey, Kiyui participates in daily orphanage activities. He witnesses Riko accidentally dislodging the Star Compass relic down a hill and observes interactions between the orphans and the Black Whistle Cravagli regarding its recovery. After Riko discovers Reg in the Abyss, Kiyui helps hide the robot at the orphanage and sees the electrical shock attempt that causes a blackout, leading to group punishment by instructor Jiruo. Once Reg integrates into daily life, Kiyui frequently spends time with him while others cave raid.

Shortly after Riko and Reg leave Orth, Kiyui contracts the typically fatal Birthday-Death Disease on his birthday. Mio evacuates him onto the Caravan Fleet for treatment, where he inexplicably recovers, becoming a rare survivor. Before his departure, Reg bids him farewell and specifically warns him against looking into mirrors on his birthday to avoid the disease.

In the game *Made in Abyss: Binary Star Falling Into Darkness*, Kiyui is the youngest orphan sharing a room with Nat and Shiggy. As a Red Whistle, the player can tell him stories (funny, scary, or mysterious) for minor rewards like Bandages or Rope. At Blue Whistle rank or higher, he requests shiny stones or ores, rewarding resources like Limber Scales or Lugworms. His dialogue expresses worry over missing peers, loneliness during the player’s absences, admiration for higher whistle ranks, and simple wishes like "yummy" festival food. Unused code suggests gifting specific ores might have increased a "Skill" stat.

Notable traits include his bond with Reg, emphasized by Reg’s bedside farewell, and creator Akihito Tsukushi’s description of Kiyui having a scent reminiscent of dried saliva.