I like option 2 if possible. I hate option 1 at the best of time, it is just very hard for me to do it and most of the time I would mess it up due to the trouble in connecting the timeline 1 (Ryuuji talking with Kaelyn) and timeline 2 (Ryuuji talking with Darya) especially if Kaelyn wants to go back to Darya once she is finished with Ryuuji, its just compound the problem. Option 3 simply not possible in this situation because Darya had personally ask for Ryuuji's presence and the store slave that she sent were seen walking toward Ryuuji would show her already that Ryuuji is in charge of the place, if another NPC manager to show up instead, it will just give the customer a reason to be dissatisfied further than they already are.