Urchin

Urchin can refer to the stages:
 * Starfish Mainstage, named after sea urchins in German, Japanese, and Spanish
 * Urchin Underpass

Or the characters:
 * Aachin, bassist of Ink Theory
 * Kitamura, drummer of Ink Theory
 * MURASAKI, drummer of Squid Squad and Front Roe
 * Murch
 * Spyke

Or the gear: