I honestly don't understand how Itsuki hasn't put two and two together yet. Her original misunderstanding was Ritsu had someone he liked, this obviously makes the presumption that it was a girl, and that was why he returned to Japan, so I can understand why she wouldn't immediately associate herself as the source of Ritsu's attention being as their gender situation is...complicated, but by this point Ritsu has straight up indirectly and directly questioned her about Itsuki's whereabouts and is shown to be obviously quite downtrodden and melancholic about his old friend. There's no reason why she shouldn't be able to realize even if not out of love, he desperately wants to find his old friend; I don't care how oblivious a stupid kid you gotta be. I get telling him the truth or otherwise being outed as Itsuki seems as though it will put into motion the end of this series, but watching Ritsu repeatedly make it clear he's looking for Itsuki and Itsuki somehow performing enough mental gymnastics to read that as Ritsu having moved on from their old friendship or otherwise should not allow herself to be found out, I just don't know.
It's the one hook in this story that really grates on me, but I still love it overall. I even don't mind the slow pace of each chapter, though I must admit the rapid releases are probably helping that quite a bit.