天王寺 裕吾

He is Okabe's landlord, who owns a TV repair store beneath his apartment, living with his daughter, Nae. Okabe often gives him the nickname "Mr. Braun" for his passion to Braun tube TV.
After seeing a gel-i-fied human in the sewers he was residing in, he was recruited by SERN, which 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 Suzuha Hashida, his neighbour, and Tsuzuri Imamiya, his future wife.
Sometime prior to the first D-Mail, Tennouji recruited Moeka Kiryuu into the Rounders and communicated with her as "FB". It was only until Rintarou and Moeka discovers his identity was FB revealed to be a man, as FB introduced themselves as a woman to all Rounders recruits.