The only instance of Hana mentioning her lingerie happens in her first event, which can only occur after she has moved in. The event where she moves in is the one directly after going to the lingerie shop.
Hmm. Hana didn't move in at all (yet) and I have 0/4 of her points and 7/12 bar events.
But you are right - after searching for it by loading different save games, I finally found that it was Maria mentioning it, not Hana. The day (Sunday) before the day of the lingerie event Maria talked about it with the MC while being with on a date (asking her in the hotel room, MC and Maria then went to the Hot Springs). That date increased the affection with Maria to 20 (could be important).
Do you need a save game to look at the issue?
One other thing I noticed (but maybe I just forget it) is the kiss with Hana that Maria mentions in the bar just before going to the lingerie store. I cannot remember that kiss happen in the first place (maybe it's just an off-screen thing?). But I will try to replay the saves, it could be that I just overlooked it.
Yes, one of the affection dates. :-)
The kiss that I mean is mentioned in the same dialog a little bit later, when Maria says: "What, we kiss? We get leeeeewd...?" and Hana says "Ehhh... I was hoping you forgot about that...". Maria then says "Of course not! That night was so fun, I would never forget it. I even got to kiss my childhood friend"
I am not sure if that kiss has happened (and I may just have forgotten about it), if it is something that happened off-screen or if it should have happened and it didn't.
I found the first meeting with Hana in my saves, then the rom-com cinema with MC, Ashley, Maria and Hana and then the travel to the beach with Maria, Hana and the MC, which seems to be the only point Hana got drunk (I am not sure why, but I don't get the beach-visit to trigger on that day again and I cannot return so many steps from the save after it, only read parts of the visit in the history, so I am not completely sure that the kiss was e.g. only visible and not readable).