You are making a very serious accusation based on your personal interpretation of a stylized art style, and I do not agree with that at all. Throwing around claims like that so casually is irresponsible and unfair.
This project uses an anime inspired style, and the characters are intended to be adults. A shorter height, slimmer build, or smaller chest does not automatically make a character underage. I understand that visual design can be interpreted differently, but all love interests in the game are adults