I already suggested the rape
tag, but the suggestion was apparently rejected. I'd love for whoever made that decision (or some staffer who agrees with it at least) to please give an official justification for not labelling this as rape. It wouldn't solve anything per se of course, but it would be good to at least have something to point to as the site's decision.
Because it does not contain violent rape, or rape at all in my opinion, it would be pointless to tag it as such since it would only clutter the results for someone searching for manga tagged rape
as it does not fall into what they would be looking for. The tagging system mainly exists for categorical purposes and as a warning for readers, if you look at the tags it says lolicon
and age gap
which should together show you that it is statutory rape and does not need the rape tag since the work does not really contain any material to support it.