Looks great..... I would love to try some.
Next time scrap the Kikkoman wannabe sauce and grab a bottle of Pearl River Bridge LIGHT (table standard in most REAL Chinese restaurants). Don't get the dark because it is too heavy and is used for cooking. PRB soy sauces are fermented and aged the traditional way. We have a huge Chinese community here in Panama and it is the ONLY soy sauce they use. You will also probably find it is less than half the price of Kikkoman (manufactured and a lot of advertising hype).
You will notice a huge difference in flavor... Don't believe me just give it a try. Also take some time to Google soy sauces I think you will find that PRB is probably number one or two on everyone's top ten lists.
Another note.... Never try DARK soy sauce with Sushi...... YUCK!