Not So Obvious After All

So no students or staff knew what "Toyoko Line" stood for. However, they did tell me a few more interesting origins of names:

Toshiba - Tokyo Shibaura Denki
(Shibaura being a place in Tokyo and Denki meaning "electric")

Sony -
a hybrid of the Latin word Sonus (sonic/sound), the English word Sunny, and Japanese slang for Whiz-kid.

Vodafone - Voice Data Tele(ph)one

Nissan - Nippon Sangyo
(Japan Industries)

NHK* - Nippon Housou Kyoukai
(Japan Broadcasting Company)

*The equivalent of the BBC