A kid and his robot best friend get caught in a corporate espionage war neither of them asked for. Signal turns out to be the only thing standing between Nobuhiko and a weaponized prototype designed specifically to erase him. The comedy stays sharp even when the stakes flip to genuine danger, three episodes that prove a robot buddy story doesn't need a TV series to hit you.

Signal is a robot built to be a companion for Nobuhiko. Trouble arrives in the form of Pulse, one of the earlier prototypes made by Signal's creator, Dr. Otoi. A mysterious rival of the doctor has reprogrammed Pulse and armed it heavily. Its mission is to steal the newest robot technology and destroy anything that blocks its path, and it soon attacks Signal. Across three OVA episodes, the story mixes comedy with mecha and science fiction.