Owner of the CRT TV Workshop set up in the first floor of the Oohiyama building. Also the landlord. Widower. Has an only daughter by the name of Nae, though he's the only one who loves CRTs. Hates LCDs with a passion, and perhaps anarchic. Though he's not quite enthusiastic in the CRT TV Workshop, for some reason he doesn't seem like he'd go bankrupt anytime soon. Nicknamed "Mr. Braun" by Rintarou, due to the loan word "Braun" used in the Japanese term for CRTs (ブラウン管).
In the Alpha world line, Yuugo lost both his parents and started living in the slums. After witnessing a jellyman who appeared near him, a group of SERN Rounders recruited him. In 1996, he's ordered to go to Akihabara to collect an IBN5100. He later acquainted Suzuha (who traveled back to 1975 and took the name "Hashida Suzu") and was taken care of by her for some time and eventually became a mother figure to him, and a girl named Imamiya Tsuzuri, who later becomes his wife. Suzu later has her body interior slowly jellyfied and dies, much to Yuugo and Tsuzuri's dismay. In 2001, SERN Rounders invaded Yuugo's house and captured Tsuzuri while she was pregnant with their second child, due to Yuugo forgetting about his mission and living a peaceful life, and turned her into a jellyman.
In episode 20, it is revealed that he's actually a veteran SERN henchman. Yuugo commands the Rounder unit (including Moeka) in Akihabara, under SERN's order to search for the IBN 5100. After Moeka successfully stole it, he was responsible for transferring the computer to SERN.
In the VN (canon), after he found out the relation Hashida Suzu had to the time machine and the future, he regretted his actions, and committed suicide to protect Nae and Moeka, as he wanted to save the latter just like Suzu and Tsuzuri saved him. His death caused Nae to become vengeful, especially against Okarin and Moeka. She later became the Rounder commander, and killed Okabe in 2025, then time-leaped 15,000 times back to the time of his death to kill Moeka and warn Okarin of his death.
In the anime, after Moeka and Rintarou found out about his identity, he confessed that he got close to Suzuha due to SERN's order. As Rounder members were to kill themself after finishing their mission, in order to protect his daughter, he killed Moeka and himself.