Ooh, that made me realize the third landlord in the Bamboo Forest is Eirin. That allowed me to move to a room she is in charge of, which in turn allowed me to walk around Eientei. Thanks a bunch.
The kicker: she cannot visit me "at home" because we both already are at home. You see, when I started this particular NG, I picked Mugenkan. .....Yes, I ended up being next-door neighbors with Eientei by accident.
That was precisely the way I interpreted it, which seems to have been wrong, after all. I thought that "close friends with one of the residents of Eientei" implied "
any one resident of Eientei", but the actual mechanic appears to be "
one of the landlords of Eientei" which means only Kaguya and Eirin count, whilst Tewi and Reisen do not. And if Kaguya is THAT difficult to catch outside Eientei, that leaves only Eirin who gets out for work 4 times a week.
So basically, the way in seems to be through befriending Eirin, then moving in to the room she is in charge of, and then talking to Kaguya. Or alternatively, not be a weirdo like me and just get in using timestop. That works, too.
P.S. Are events where girls jump you instead dependant on the route (Love or Lust) you take with them? Like Gengetsu nightcrawl or Sakuya timestop, to name a few. Or does it happen regardless of the route itself and rather a matter of affection stats in general?