Young Nobuhiko has been given a chance of a lifetime. He gets to design the personality of Dr. Otoi’s latest and greatest robotic creation - “Signal”. Signal is a robot that looks exactly like a human, is designed for combat, and comes ready for action. A true accomplishment - but Nobuhiko only sees this as the perfect chance to finally have a big brother. Unfortunately, Nobuhiko’s plans take a turn for the worst when he blunders in the laboratory and things are forever changed. The mishap causes Signal to develop a split personality. There’s the action-ready Signal and the chocolate chomping chibi-Signal. The unstable balance of personalities also switch at the worst moments because it happens whenever Nobuhiko sneezes.