The prototype for Signal made by Otoi-sensei and Masanobu. Originally he was seen with silver hair and a grey styled outfit. He was a very kind and gentle robot but then one day Masanobu made some changes, upgrading him into a highly skilled combat robot. His look then changed to black long hair and dark clothes with two massive blades connected to his arms. It also appears that he conducts electricity through his hair and then charges that power through his eyes like a laser. These changes were not entirely for the best. Now he seems to be VERY nearsighted and if he should happen to use the laser or get too worn down he passes out. He has what appears to be robotic narcolepsy. He and Signal constantly fight and tease each other, but Pulse seems to have a soft spot for Chibi Signal and often talks with him. It also appears he was/is friends with Kris.   

Signal, a robot companion built for Nobuhiko, is attacked by Pulse, one the its creator's previous prototypes. Reprogrammed by Dr. Otoi's mysterious rival, Pulse is loaded down with weapons and sent on a mission by Otoi: steal the most recent robot technology, and obliterate anything that gets in his way.
 
(Source: Anime News Network)

[Blog](http://koyap.jugem.jp/) | [Agency Profile](https://tsf-official.com/talent/takehito-koyasu/)

Koyasu is the most prolific voice actor in the industry, having been credited for over 700 roles as of April 2022.

Growing up, Koyasu skipped out on going to school to watch movies at home because he wanted to become an actor. It wasn’t until later that he became interested in voice acting after having seen [Galaxy Express 999](https://anilist.co/anime/1491/). After graduation he entered a voice acting school. In 1988, he made his voice acting debut, and got his first regular role a year later voicing [Gai](https://anilist.co/character/13374/) in [Tenkuu Senki Shurato](https://anilist.co/anime/2113/).

Though having voiced more characters in the medium than anyone else, he is probably most known for his role as [Dio Brando](https://anilist.co/character/4004/) in [JoJo’s Bizarre Adventure](https://anilist.co/anime/14719/). He has stated that he likes playing villainous characters.

Koyasu has taken over many of [Kaneto Shiozawa](https://anilist.co/staff/95424/)’s roles after Shiozawa’s passing.

Father of [Kouki Koyasu](https://anilist.co/staff/219102/).

__Non-Anime Roles:__

- Olivert Reise Arnor - The Legend of Heroes Series (VG)
- More - Metaphor: ReFantazio (VG)
- Mustang - Goddess of Victory: Nikke (VG)

It follows the story of a humanoid created by a robotics expert named Dr. Otoi for his grandson, Nobuhiko. But in the process of writing and applying the programming, an unfortunate mishap takes place! Nobuhiko sneezes. Now, whenever Nobuhiko sneezes, the humanoid (named Signal) transforms from a temperamental adult robot into a chocolate-loving baby version of himself. 
Despite this little error, the days spent with the Otoi crew are usually fun. Animals, people, and robots all can live in harmony. 
Until one day, Signal is attacked by Pulse, a robot created by Dr. Otoi some time ago. Much like a prototype for Signal. Pulse is incredibly nearsighted, but makes up for what he lacks in vision with firepower. Dr. Otoi's mysterious rival has packed him to the brim with amazing weaponry, with the intent of stealing the Doctor's most recent robo technology. 
(Source: Wikipedia)

The sequel picks up the plot two years after the end of the battle with Dr. Quaser, and a think tank named At Random is attempting to apply robots to daily use for the public. The setting is in Singapore. The new story focuses on three characters: Lantse, a successor unit to Pulse; Maria Maria, a girl who is depressed after she suffers from an accident; and Shiruto, a boy who wants to become a robot. A 13-year-old Nobuhiko, a 19-year-old Chris, and Signal will also appear in the story.
 
(Source: Anime News Network)