As one of the sailor senshi, Michiru is a rather desirable captive either in civilian or senshi form, as she is very nice to look at from head to toe. It's often best to capture her in her swimsuit in civilian form to be able to admire her curves, but her senshi outfit provides the same nice view for free. Of course she needs to be taken by surprise to keep her from attacking, as she doesn't allow people to tie her on a casual basis very easily. In the off-chance that she's captured, emphasize her hips, lips and eyes with the binds and gag. It isn't safe to stick around with her for long since Haruka will come looking sooner or later.