Well, this comment section went nowhere quickly. As usual, though.
There really is no need to jump to conclusions and start labeling things. Oshimi is a very reasonable person, and his issues with masculinity and self-image might well stem from something as common as low testosterone supplemented by judgmental or abusive attutude from others experienced during his teens.
I think it's a great thing that he's trying to figure this out through writing, basically trying to envision a situation strongly resonating with his own but hyperbolized just enough to let himself draw conclusions that his personal experience did not provide, or different in just such a way that would put his standing ideas and convictions to the test. And that's what's most important in my opinion. This is writing at its finest; an experiment jointly participated by the author and their audience.