[X] Shadow The Group. (Your earlier spying proved the owners couldn't detect your presence as a ghost. Nel can wave off your apparent absence later if need be, though doing this too many times may raise suspicion among the others.)
The others are introduced to Kikuko about her attempt at spying, unfruitful it may be for now. If they aren't against it, I think doubling down on that isn't that bad of a thing, show to the rest of the team that you are attempting for that spot in the role dynamic.
Downside is that we miss out on the first full team bonding experience, and establishes a divide between Kikuko and the rest. But I think that's going to happen anyway if secrets are kept, and the worst case scenario is a time-sensitive need for Kikuko to join in combat, but chances are what 4 rookies plus a mentor can't face is not easily solved by one additional rookie, and by that point secrecy is least of the problems.