THANK YOU! I might have found it, eventually - like a year later lol. I thought maybe, when I saw the name a bell would go off in my head. But nope, this doesn't sound familiar at all. I also don't remember the boss's dialog being in Japanese. I Googled it and it looks like it was only released in Japan, so the ones I played must have been imports.
This game is SUPER! It's pretty damn hard, but lots of fun. And oddly enough with the default dip switch settings you only get 5 continues. I do remember a few arcade games back in the days that limited your continues. Which I never understood since I was spending money to play. I HATE altering dip switches in MAME to make a game easier, or give me more continues. But I think here I have to cos no way I'll ever damn beat it on 5 credits.