I am now stuck, and lowkey pissed. I know for a fact that you can access the lair with Tsuyu, I did in a previous version, I even had the save for it. But for whatever reason, no matter what I do, I can't now. The option to invite Tsuyu straight up doesn't appear. And before someone tells me to just progress her story further, I invite you to please read the rest of the comment, and then tell me how.
After the scene on the beach with Tsuyu and Midnight, the game says "There's something else to do first" whenever I check on Tsuyu. That's the only hint I get, and it's useless. I've searched this thread for people also having this problem, and almost all replies are some variation of "I'm stuck too", and a single "Do quests for the other characters". I tried that, and it didn't really work. Toru? "There's nothing to do right now" Momo? "I still have work to do with Jiro" Mina? "There's something else to do first" None of these are available at this point in the game so Imma cross them out. Ochako? Progressed until I reached "Improve relationship with Mei". Mei? "Explore the cave near the beach", so whatever it is, it can't be them. Jiro? Did all I could up to the movie, after which the game tells me "Jiro's content ends here, if you haven't finished the main story please do so". Eijiro? "Nothing to do until further update". So my only options are Nemuri, Shota, and Sone, and all of them are blank. I tried going to every location I have access to, at every time of day, and seemingly nothing progresses the Tsuyu story to the point I recruit her.