Description
Discovered by Iori Minase during a rainstorm at a shrine, Haruka-san is a Puchidol resembling Haruka Amami. Water exposure triggers her distinctive trait: exponential multiplication. Contact with water can also unpredictably trigger drastic size alterations, ranging from ant-like diminishment to colossal, boat-sized proportions. Temperature influences these reactions; warm water above 34°C does not cause multiplication.

Haruka-san moves primarily by hopping instead of walking and rarely closes her mouth, even while asleep. Displacement of her hair ribbons induces a reversibly dark, demonic transformation, corrected only by refastening them. Feeding after midnight similarly induces a dangerous behavioral shift.

Haruka Amami formally bestowed the name "Harukasan" upon the Puchidol's arrival at the Project 765 office. An accidental water spill soon after caused widespread replication and significant office destruction. Haruka-san appears in manga, special OVAs bundled with Blu-ray/DVD releases, and the fifth manga volume. In the game "THE iDOLM@STER SP", she functions as an equippable accessory that enhances Vocal stats when worn.