Sekaiichi Hatsukoi Movie: Yokozawa Takafumi no Baai

Although the art isn't anything alike and the most alike to this movie is going to be either Junjou Romantica or Sekai Ichi Hastukoi which are both by the same author, I thought it would be a good one to add. -Men who work together and fall in love -Heartbroken romance(Side character) -Both have a 'large mystery' to figure out -both a movie -'Uke characters' like and do good with kids -Both inlude stories about someone's child that is intremental in finding the resolution -Both have feelings for the other side but maybe aren't willing to accept it. And the one I appreciate the most- -Both couples are aware of the other's feelings and accept(in hatsukoi-grudingly)the advances. They don't fit under the same genre as Hatsukoi is stricktly a romance and Fake is a mystery but I feel like the romance in Fake fits nicely next to Hatsukoi's. They are just similar enough in several respects that I think that if one is enjoyed the other could also be(ane maybe even be liked more).  read more 

Yaoi/shonen ai which has tsundere uke, somehow there is a child girl there, and there is a blackmail somehow too and a persistent seme somehow too, again. One is a movie and the other ovas but the duration is practically the same. And of course Koisuru Boukun is more explicit.