I would suggest that someone in the party owes her a favor, and when she comes to collect (perhaps noticing us by happenstance, such as from Robyn's matrix activity), we first ask her to help us finish the job before any of us can help her with her little problem, whatever it may be.
Also, Jackhammer is often involved in underground fights, so if Yukika is a gambler, she may well have bet on (or against) him at some point. Just an option, should you choose to explore it.