Anixx's comment about underage girls being a "blank sheet of paper" tells me that he wants a girl whose mind has not developed.
I have already specifyed what do I mean. This mostly means that their brain is not polluted with

- experience with other men (especially, negative experience but positive as well)

- religion, politics etc.

- mercantilism

As for me, my husband is 8 years younger! So I am certainly not opposed to dating people who are younger or older, as long as both people in the relationship are adults. He was already 27 when we met.
This is the outcome of your feminist society. Your state prohibits him to meet with younger girls and his peers are too inaccessible for him. So he has to mate an older woman. For a 27 years old guy it is more natural to meet a 16 or 17 years old girl than a 36-years old woman.

By contrast, if I had been 20, he would have only been 13 - and that would have been too young.
As I already said, adult women usually have no sexual attraction to teenage men. Cases of women's pedophilia or other relations with underages are very limited in number regardless of whether it is prohibited. This is a clearly anti-male law.