@GTX1080Ti Japanese authors have been writing weird romance even before they were legal. There were tons of homosexual romance and underage romance available for years, some could be found even in the 80's... maybe even older...
Besides, it's not illegal to write about incest.
@GeNtLeM4N Wait, the summary literally stated that this would happen. It's tagged incest.
How the heck did you miss that?
@Greenfrost No, the tragedy is finding out that they are siblings. Also, the idea that kids born from incest having defects is blown out of proportion. It's when there is too much inbreeding that it's a problem. One or 2 generations isn't much of a problem. So the kids would be fine.