I think I know where this is going.
The author is going to showcase how young men may be affected in the Host Club debt trap cycle. It doesn't have to be Host Clubs. Generally, it's some type of entertainment agency the girl benefited from and is dependent upon. It's pretty common to see girls fall for it. But it's less often known how some of these girls in peril latch onto an unsuspecting man to save them. Some maliciously, some genuine. Often these boys have serious vulnerabilities, and the girls come with lots baggage (mostly external).
In this case, our MC is a prime candidate, but I do believe FMC is genuine.
So I'm guessing Sensitive Boy is just about the lesser known sensitive problems that boys/men may go through? I wonder what the next boy is about.