[tokyo-yokohama]

(morning, formal) Ohayoo Gozaimasu (Good Morning)
(morning, informal) Ohayoo (Good Morning)
(afternoon) Sayoonara (Good Afternoon)
(Evening) Konban Wa (Good Evening)
(over phone) Moshi moshi (say fast) (Hello[Phone])
That how you say all hello in Japanese.
I know, I live at Tokyo. Sorry for bad english.