At the end of episode 12 of Amnesia, what does those 5 cards stand for? Also is there a continue to what happens in the manga?

The 5 cards stand for each one of the boys.
Shin - Heart
Kent - Clover
Toma - Diamond
Ikki - Spade
Ukyo - Joker

The Heroine can pick one of those cards to choose which world she wants to go to.
(Like if she chooses Toma's world, she will be with Toma.)

I am not sure what happens in the manga, but I bet it's similar to the anime.
I just know that Amnesia was a game before the manga/anime was created of it.

In the game that "5 card standing"-scene wasn't the end. You have to pick a route (card) and the game will go on with the one whom that card belonged to.

I believe they have added the possibility to have either good or bad ending with that certain person depending on how you play.

Hope this helps :]

Actually after Orion explain everything to Heroine, he told her that Neil would be more than happy to restore all her memories and lead her back to her original world. The last episode very clearly demonstrates that. After she goes through the white door way, she loses her memoires of Orion and everything that has happened- so basically everything goes back to normal for her. I wish I knew what boy she really ended up with!!!!<3

Hey, just thinking, I know it's an open ending so that everybody is happy, but Neil said about her returning back to her to her original world, and as that was were she was with Ukyo, it makes sense that that is where she ended up :)