In order to see Kousei, your daughter must eith go to the red light district in the back ally or work in the moving service with the morality of less than -40 after entering junior high.
There are two different endings that one can achieve when marying Kousei, a good one and a bad one. One achieves the good ending by having low pride (under 80), and bad ending by having high pride (80 and over).
Kousei opens his own company, which does extremly well and become very sucessful. However, after achieving such sucess, Kousei lose interest in the company (he doesn't find the challage) and quit. Kousei sell everything and decide to move to monglia, asking your daughter to come along. Your daughter will reluctantly agree, and ask Kousei why they came to monglia. Kousei replies that he plans to conquer the world, just like Genghis Khan . To which your daughter will replay that he's hopeless, and that it's just like him.