OFFICE BUILDING INFILTRATION

They're in Tokyo. Season 49 of Murder Manor has just finished airing and there are some difficulties in preparing the DVD distribution on account of the numerous references Chiaki Nanami made to popular copyrighted Nintendo games. Kaoru is pretending to be the representative from Nintendo who has come to the Murder Manor office building: as a Japanese guy in a nice suit he is pretty convincing. He does various shady things which are left to your discretion; I'm not sure if this is supposed to be all in one day or multiple days and if he kills other people in the meantime.

Kanaya is not personally infiltrating the building because she saves her disguises for emergencies. (People have learned to look for a woman wearing a really huge hat and absolutely ridiculous amounts of foundation.) So during this part of time they're just in contact snarking about the mission via text message or headset phone.

THE CLIMACTIC REUNION: Kaoru is convincing the highest-ranking final target to come with him to the rooftop for a completely routine helicopter ride. Kanaya is in the helicopter. When the high-ranking person gets into the helicopter, they do not expect Kanaya to be in there with gloves and strangle them with their own necktie, which she subsequently makes appear to have gotten caught in some machinery. This is because they crash the helicopter as this person is so high-ranking they need to have seemingly died in a normal way as opposed to being obviously supermurdered.

Kaoru and Kanaya jump out of the helicopter before it crashes of course. Kanaya was never officially there; Kaoru's nintendo guy persona was presumed to have already left the building. Then Kaoru hotwires a car while Kanaya starts typing up the notes he stole or something.