Eleven-year-old Nobuhiko Otoi is going to the countryside (Tokkari Town, to be exact) to live with his grandfather, Professor Shinnosuke Otoi. His parents have gone to work in another country, but they do so much traveling they decide to leave Nobuhiko with his grandfather on a permanent basis.
Once there, Nobuhiko finds out that his grandfather has made a new fighting HFR called Signal. He persuades the Professor to reprogram Signal from being a battle robot to being his older brother and friend. During the programming, an accident occurs resulting in Signal transforming into Chibi Signal whenever Nobuhiko sneezes. Unfortunately, Signal's aggressive battle programming wasn't changed yet so he is somewhat scary by Nobuhiko's standards.
Story and art by Sachi Oshimizu.