The fact that Ayane is a ninja is alone to warrant heavy caution in trying to sneak up on her as she can sense one's presence and intent fairly readily. It's far easier, and well worth the time, to earn her trust in allowing herself to be captured. She's a bit of a tsundere and may have some harsh words, but she can escape fairly easily if she wants to. Don't let her wonderful chest fake you out though, her weak spot is actually the back of her neck. She'll feel insulted if she's not tied in a manner that would provide a challenge to escape from, so make sure to keep it heavy. She doesn't like tape, so stick with rope or straps.