Your point stands to no reason, given that, while 18 was made for legal reasons, it was also made to preserve a childhood and prohibit inappropriate use of children (aka for work, militia etc).
Age is also not JUST A NUMBER, as it’s known widely that you truly mature psychologically even over 18, your impulse gets reigned in and you enforce your beliefs. People who have gotten taken advantage of as children (under 18 or so) have developed certain habits that are destructive, ie, a sexual abuse victim may become hypersexual if they’ve gotten abused in childhood rather than later on in life solely because they didn’t have psychological resources to handle such a thing.
You know absolutely nothing about why 18 is the standard, and why it’s predatory to go for someone below it (some arguing even below 20).
I like to read dark romance with such taboo relationships, but in the context of “this author isn’t romanticising it, they’re exploring it” whilst this is purely to cutiefy. You can read this manga sure but don’t put down a real world issue to morally exempt yourself.
Y'all do know that the whole thing of not engaging in romantic and sexual relationship before 18 is literally new throughout human history what was considered "appropriate age" was determined by random men and after our era has long past a new age restriction along with new laws and philosophies will be created as well it's not a fixed thing so basically y'all fighting over a fugazi a non existing thing said by random people and were taken as absolute truth. Fools