There is a lot to unpack here...
Firstly, I get that this was made in Japan and their age of consent laws are different than those in the US, but still why you got to show damn-near naked depictions of characters who are so fucking young knowing well enough that this will find its way to a western audience? Not to mention the scene where Nao goes shotacon on Kazuki was unnecessary and needlessly meanspirited. Don't come at me with that "well it is kinda in their character to do that" argument because that didn't have to make it to the final cut. Secondly, the whole arc of this chapter with Kazuki's story (aside from what I previously stated) is just disappointing. I say this because the allure of this series to me was it's respectful approach of depicting how a character comes to accept transitioning to another gender identity, and romantic relationship between a trans and cis character in the backdrop of a society that doesn't fully understand or accept the existence of trans people and their relationships with other trans or cis people. Kazuki comes into the equation because he (yes I said he, sex and gender are two different things) could have been a very good character for exploring the experience of trans-men and trans-masculine people, or trans kids as a whole. Id est, exploring how it must feel to see yourself as one way only to have everyone else and your own body to suggest the opposite. Only for that theme to be dropped because the author seemed to be either horned out of her mind, or making an attempt at fanservice.
Maybe things will change as I read further into the series, but as of writing this, this chapter is a low-point for me.