To be honest, this pairing is the most beautiful thing in this manga. Akira is not a pedo, the girl he love just happen to be a little girl. He don't love any girl, just her. At first he don't even like her. Now he decided to wait 11 years to tell her his feeling. (That'll make Ami older than all the girls in this mamga right now to know the feeling of the man she loves). Pedo definitely don't do that. I didn't say pedo is good, just he is not pedo.
And Hirofumi did that because he do not want to hurt Ami by seperate them. He know Akira means a whole world to her.