Spoiler (highlight to view)
He sleeps with the woman he met at a job interview when he finds out Ageh is pregnant. The pressure of finding a job with that drove him into a depression which the other woman played on and he left Ageh to be with that woman.
His one scar friend I believe wanted to sleep with Ageh, because he was in love with her. She turned him down as she turned down that photography guy as well. Same scar friend came to where Tsutomu was staying and they beat the crap out of each other and he made Tsutomu wake up. He goes back to Ageh, she pimp slaps him then she forgives him. They get married and have a little girl. The end.