"bainara" - play on and mix of sayonara
and bye bye
becomes "bai" in katakana
"bai bai kin" - play on bye bye and the japanese word for germs, "baikin". Originally? comes from a CM for dishwashing soap where a little girl says this phrase which means "bye bacteria".
"genko" - play on genki.
"yoropiku" - play on Douzo yoroshiku.
"daijyoubi" - play on daijyoubu.
"sunmason" - play on sumimasen. Originally phrase comes from a tarento (or was that a comedian?). wasureta!
"yorochikubi" - play on yoroshiku by mixing with chikubi - "nipple".
Also, some greetings below are ones that you wouldn’t want to say to anyone but your shiftless friends. The thing about these is to say them quickly enough that no one notices, but they think that something is strange about what you are saying.
"gomen oppai" - play on gomen nasai, which is like sumimasen.
oppai means breasts
"yarashiku onegaishimasu" - play on yoroshiku onegaishimasu.
yarashii = adjective which is like "dirty" as in ecchi or hentai
"tadaimanko" - play on tadaima. manko is vagina in slang.
"suumanko" - play on sumimasen. same as above... but in addition, suu means to suck or smoke