Por que no los dos?
Maruyama laughs into the next world and is followed by Takada who needs to let him know she was serious. Spin off shenanigans, 200 chapters, then finally a real confession before they make it back and start dating. Anime soon after.
I'm assuming that was a video call so guessing all that it would show is that a call had taken place. Perhaps enough for our ace detective to figure it all out though. Unless, I don't know, hacker magic.
It would be nice if by the end of the arc the Tomoki siblings mended their relationship a little bit. Kuroki has had some growth after all and isn't as cringe as she was... at least in reference to her new friends.