Yuugo Tennouji

Yuugo Tennouji (天王寺 裕吾 Tennōji Yūgo) is Rintarou Okabe's landlord and the owner of the CRT store.

Personality
He has a great passion for CRT Television and refuses to upgrade to any other type. This coupled with the fact he owns a CRT store has resulted in Rintarou nicknaming him "Mr. Braun" after the inventor of CRTs, German physicist Ferdinand Braun and the common Japanese name for CRTs, "Braun Tubes".

While appearing as a tough and menacing man and often using this demeanour to jokingly bully Rintarou, he actually has a soft spot for the lab members and cares about their well-being. His daughter Nae is his top priority and he will go to desperate lengths to ensure her safety.

Yuugo has a bad temper, and is very easily annoyed by Rintarou's mannerisms as well as his "experiments" upstairs. He even threatened to raise the lab's rent money should the experiments continue to disturb him, though this as never actually happened.

In the presence of both his daughter and Rintarou, he would often attempt to "protect" her from Rintarou, whom he sees as a "pervert", though he was likely joking.

Background
Yuugo was an orphan living in Paris. He grew up living a rough life in the sewers.

At some point during this period, he was contacted by SERN and offered a position as a mercenary, this provided the money he needed to get out of the slums. After a while SERN ordered him to go to Akihabara in Japan, it was here that he met Suzu Hashida, his neighbour, and Tsuzuri Imamiya, his future wife.

Sometime prior to the first D-Mail, Tennouji recruited Moeka Kiryū into the Rounders and communicated with her as "FB".

For the first half of the story, Yuugo only appears as a mean landlord to Rintarou. However, when Moeka got cut off from FB, Rintarou decided to work with her to track down this mysterious person, who turned out to be none other than Yuugo himself. The three had a brief conversation before Yuugo/FB, realizing that his usefulness to SERN has run out, draws a gun and commits suicide, much to Rintarou and Moeka's horror.

When 1% Divergence is obtained, Yuugo is seen running his shop, having apparently never worked for SERN in this world line.

In the anime, Yuugo shot and killed Moeka before killing himself.

Appearances
Yuugo appears as a side character in Steins;Gate and most subsequent spin-offs, with the exception of Braunian Motion of Love and Hate, in which he is the main character.

Robotics;Notes

 * In Robotics;Notes Mr. Braun is still alive and as doting on his daughter as ever in August 2019 in the Steins Gate world line.(1)

Trivia

 * Yuugo's callsign of FB is the acronym for "Ferdinand Braun". Yuugo himself confirmed this shortly after Rintarou discovers his identity.