I didn't want to make the dragon too much angry! To be serious: We made some pieces with the wasabi directly inside, but most of the time, we left it to be put on the piece only before you eat it, because not everybody likes the wasabi. I like soja sauce with it as well and once heard a japanese sushi master say, that it's a sin to let the wasabi touch the soja sauce. He said you always got to put wasabi on one side of the sushi and dip the other side into the sauce.