Yappari (or yahari) is a Japanese word that has several meanings and uses. The one that is the most interesting is where it means 'of course' or 'as expected'. It is used all the time in everyday Japanese, and an equivalent thing in English could be the use of 'you know', when most of the time it's used, the other person didn't know or expect whatever the speaker was saying to be a fact. For example:

「おれが思っていたおり、やっぱりあの人は嘘をついていました。」

ore ga omotteitaori, yappari anohitowa uso wo tsuiteimashita.

"Just like I thought, he was lying - you know."

I could go on to explain it in more detail, but it's been done already (and far better than I could ever explain it): explanation of yappari. Anyway, if you're in Japan - you'll hear it being used all the time. The other thing you'll hear is that the Japanese really want to speak English, of course!