Personally, I wasn't interested in watching this, since, most of what was going to be shown as already been shown as flashbacks in the drama itself. Nevertheless, it's worth watching. In Rich Man, Poor Woman Episode Zero we see how the Toru got involved with Asahina, how the name Next Innovation was formed, how Tohno got involved with Next Innovation and also what led to his leaving Next Innovation. We also see how and when Mr Yamagami joined Next Innovation. Generally, it's just about how Next Innovation grew and got into the stock market. The cast is the same as the original cast from the drama, there is no unknown cast :). The acting also didn't fall short, plus, this is just 11 minutes and some few seconds long.