It's "Moshi Moshi".

Honey, next time you're going to try to "out-Japanese" some other random non-Japanese anonymous on the Internet, you should be aware that there's more than one romanization system--and in the one preferred by a lot of Japanese people, for instance, the "shi" sound is commonly written "si."

"moshi moshi" desu

もしもし、だボケ

きょんくん、でんわ～

>>344
If it's preferred by Japanese people, then why is it that Tokyo Metro and other subway/train companies here use the modern Hepburn romanization system?

I've been in Japan more than 6 months now and have never seen し written as "si." I've been in cities and the countryside.

Myself, I prefer to write out each sound. Example:
ありがとう would be "arigatou"
帰ってください would be "kaette kudasai"

>>518

It just depends on the standards set by each group. Those companies are supposed to be readable by foreigners, so they don't use the standards set by the government. They make it more readable. The friends I tweet with type stuff like "siitake" (and Tukiji) all the time. A lot of institutions use more foreigner-friendly romanization systems (which I prefer too), but a lot of individuals don't.