The only consistent aspect of Tominaga's animation i've been able to identify him by so far is his spark FX. It really sucks his credits aren't as complete as other animators because i'm sure he's done way more than the few things i could find listed.

What is it about his sparks that stands out? The way they arc?

It's kinda hard to explain but i guess its the fact the sparks always never have a uniform width and look more like blades of grass after they splay out from the origin point. I don't know if I'm making sense but yeah :P

I think I know what you mean. It actually reminds me a little bit of hidetsugu Ito's sparks, but they definitely have their own flair.