The boob mistress Haruka makes a few non playable forms in both Burst and Portrait of yong girls, both are pretty much the same and I will quickly go over them in this short character breakdown.
As a boss characcter Haruka has a few advantages one is that she does not have a ninpou meter so at any time she can use a ninpou against you. While her attacks are mostly slow and predictable she has one ability that she does not in her playable form and thats to jump and throw tubes as a normal attack and she throws 3 at a time. The would be an intresting move if she keep it. Like her other form once she loses her coat thats it she can't use her test tubes. As for ninpou's her first and second act diffrently the kiss of death is restricted to just a close range attack and her second ninpou does not damage you but your clothes bar so you will lose you clothes if your hit by it. Haruka funny enough is the weakest boss and can just be rushed down with any type of attack
In burst as well she is a pretty easy boss so she is never a threat even though she is the oldest.