The second season of Weiß Survive.

Someone out there is determined to see the fall of Weiss Kreuz, and it looks like they have found the perfect plan for it. The four assassins find themselves trapped in a deadly game of deceit, where the question of honor versus duty comes to surface. Now they must fight for their own reasons to survive--and there can be only be one victor in this field of death. (Source: AniDB)

Takeshi was just an ordinary guy until a perfectly innocent study session with Michi - the most beautiful girl in the school - ended up with him being mysteriously transported into the strange dimension known as the Weiss Schwarz Battle Space. Once there, a crazy but enthusiastic old man informs him that he is the chosen warrior and must win a succession of card battles to get back home. The only problem: he doesn't know how to play! However, with the expert Michi ready to teach him the ins and outs of this bizarre and improbably slapstick card game, Takeshi will learn the ropes and get ready for the card battle of a lifetime. Assuming he survives the training... (Source: ANN)