I never really understood why EVERY character that is either cumming or experiencing some form of pleasure is pretty much always crying. Like, it looks like they are in pain. If it wasn't for that Kamitora's art would be in my top 5.
Tears/crying fetish is its own sub-category of fluid fetish. Just like most people love the abundance of sperm during ejaculations in these images, the tears are the cherry on top for some people. It's not my kink but I understand it.