The main character and namesake of the series Signal is the newest HFR Human Form Robot to be created by Professor Otoi. He is unique because of the MIRA and SIRIUS technology in him which sometimes makes him a target of those wishing to steal his data. He is programmed to be a fighter and an older brother to Professor Otoi039s grandson Nobuhiko. Due to an accident in the lab during his creation when Nobuhiko sneezes it transforms Signal into a much smaller version of himself. He is referred to as 039Chibi Signal039 is very hyper and adores chocolate.