Hey, I know it might be late to ask this, but is there an ending where you end up with Polar? I'm just asking because I haven't found one yet.
No, never too late to the party. There is definitely an ending where you end up with him, it is tricky to get (mainly cause the other guys routes have the potential to derail you off his, if you let them) and there is only 1 way to attain it. While there is no official guide, there are def some posts on Lemmasoft Forums that I'm certain can help.
https://lemmasoft.renai.us/forums/
Then search for "Dream Savior Gakuen".
My reply might be too late, but the way to get the polar Ending is just to refuse all of the other 3.
and here's the exact response