These dramas are near opposites which share the same catalysis of the government creating a program to increase Japanese birth rates.

Otona Koukou doesn't take this premise seriously at all and instead uses it as a premise for comedy amongst a fun cast of characters. Kekkon Aite takes this concept as seriously as it can to make a political statement about the social consequences this program would have on various Japanese minorities.

Both share the similar traits of having well-written and respected queer side characters who are given lots of plot relevance. Both also ultimately end up sharing the critique of the failures of this program in creating a long-lasting healthy relationship.

Both series follow a monster protagonist who struggles to balance the importance of human and monster lives.

Both seasons feature similar plot twists that further develop the characters from the previous season.