I'm also sticking with P3P. It helped that P3P is $20($15 when I got it on a Steam sale) and P3R is $70.
This is a bit of an unusual pair, since Yukari arguably gets along worse with Aigis than with Mitsuru(at least on the male protagonist route, when Yukari gets angrier about Aigis' closeness to the protagonist), which isn't helped by how Aigis joins after Yukari starts warming up to Mitsuru a bit. Despite this, the two have a nice reconciliation moment at the end of The Answer.