From Siliconera - "Usually, dating sims end with the protagonist winning a girl or guy. A happy ending with a dream date is the genre's reward. Dream C Club's courting process has players pay to spend time with virtual hostesses in hopes of winning their heart.
But, you can't win Amane! After spending over tens of thousands of virtual yen and dozens of hours trying to woo her a 2ch poster discovered Amane sacks the player in the friend zone by saying "You're my closest friend, aren't you?""
After beating the game and getting dumped you get 10 gamerscore points and the Dream is Over achievement.