After Sayaka says " Minna-san konnichiwa", she also says right after that: "Mata ai mashita me" (I guess that's how you spell it) So what does "Mata ai mashita me" mean?

Konnichiwa! またあいましたね。Mata aimashita ne. means "We meet again!" MATA is "again" and "aimashita" comes from the verb AU "to meet" and the NE adds a familiarity to the phrase. Something like, "Hey, we meet again." -Sayaka :P

what we say hello goodmorning in japanese?

@Sahil Hello= Konnichiwa Good morning= Ohayo gozaimasu Hope that helps.

and what we say thank you in japanese?

Thank you=Arigatou/ arigatou gozaimashita

How are you?= O genki desu ka? Thank you= Arigato Hello= Konnichiwa I am well= Genki desu And you?= Anata wa?

I think "O genki desu ka?" does mean "How are you?", but as a concern of one's health.

Literally, it does translate as this(in concern of health), but it is also used casually to simply mean "how are you"

It certainly is used for 'how are you', but I would say not in quite the same way as we use that in English. It seems only commonly to be used after a longer absense or lack of contact. In English, you can say 'how are you' to someone you saw yesterday & it sounds quite normal, we often dont really expect a reply. But it seems to me that in Japanese this would be a bit odd. Some native Japanese speakers confirmed that for me, they would not expect to be asked 'お元気ですか’ say twice in two days by the same person. They also felt that whilst it did have the more general sense, it does retain more of an explicit enquiry after your wellbeing & health than the English usage. As ever, the nuance..............

Yep, you're right. I overlooked the fact that people meet more than one time in a single day. Thanks Hnrutt