Tough, sassy, and angsty isn't really specific enough. I don't really know who you're talking about (Miho or Amon's ex-girlfriend Takako(?)), but this character is definitely not one you would consider angsty.

It's Michael or the young, impulsive one either. (It's been a while since I watched it. I think his name is Haruto or something like that.)

And, no, not the bald guy.