Here's what I can remember:
- Anime style, relatively recent (within the past few years)
- Fantasy setting
- The king has recently either died or is about to die
- The princess is due to take up the throne
- You play as a male protagonist as a member of the court, position is something like an alchemist or the prime minister
- Your goal is to corrupt the princess before she take the throne since she hates you and will get rid of you once she ascends to the throne
- The princess has a bodyguard / friend who is in love with her
- I believe that there is a crystal ball involved as well