Saikyou no Kurokishi♂, Sentou Maid♀ ni Tenshoku shimashita - Vol. 7 Ch. 42

[MangaDex]

 

[jomamaphat]

I’m pretty sure underage marriage is legal there

 

[Scrabbleman]

"I received a letter from a little girl"

"Hello, 911?"

 

[1234muse]

=_=

 

[Yankun]

I’m pretty sure underage marriage is legal there

Twelve is not underage.

Well, not at the time this setting should be.
So the matter is beyond legal or not.

And even if marriage is impossible, there's the practice of engagement.
Plenty of ways to have a relationship with a young girl. lol