I've tried making my own tamagoyaki a few times, but I can never get it quite right. I guess it doesn't help that I don't really have the right kitchen equipment. I did use a little sugar, about a teaspoon, I think, and a little soy sauce if I had some.
Personally, I like the taste of fluffy, slightly sweet omelettes, but I don't think you have to add the sugar if you don't want to. You can try using less sugar than your first try, or leave it out altogether.
>>2 'Tamagoyaki' is Japanese for 'grilled egg'. It's basically a Japanese-style omelette roll, consisting of several layers of egg.