The description explicitly says entering senior year. They could have easily made it so they were entering college. Its still a porn game about high schoolers. Anyone can use all the thermian arguments to justify why its technically legal, but its still a porn game about highschoolers. College exists and is for adults if an academic setting is needed or they need to be students. The fact that the creator said they're 18 proves my point. They would only do that if they know making porn of minors is wrong or knows people will rightfully criticize then for making porn of underaged teens. They want them to be highschoolers, be in a grade where they would reasonably be 16/17 like in the original, but still had to clarify that they are technically legal. If a creator has to clarify that the characters are technically legal despite all common sense saying otherwise, that truly speaks volumes.
This is more preemptive and not directed at you specifically; I'm not slinging insults or being vague and unreasonable. I'm leveling serious criticism that any artistic would would face upon reaching the public. If the artist/creator cannot reasonably justify why making them high schoolers in a pornographic game is needed and the work would be worse without it being porn of high schoolers, then why are they teenagers in highschool. If they were 18 then they'd be graduating. Its just that simple. A throw away line simply highlights the fact that the criticism was valid enough that it needed to be addressed, Because again: This is a porn game about highschool juniors(typically 16/17), based on a porn game primarily filled with underaged characters.