Music Video of the single A song for You! You? You!! from μ's.

A young wavemaster, only known by the alias of Tsukasa, wakes up in an MMORPG called The World, with slight amnesia. He does not know what he has previously done before he woke up. In The World, the Crimson Knights suspects him of being a hacker, as he was seen accompanying a tweaked character in the form of a cat. Unable to log out from the game, he wanders around looking for answers, avoiding the knights and other players he meets along the way. As Tsukasa explores The World, he stumbles upon a magical item that takes the form of a "guardian," which promises him protection from all harm. Subaru, the leader of the Crimson Knights, along with several other players who became acquainted with Tsukasa, set out to investigate why Tsukasa is unable to log out, and attempt to get to the bottom of the problem before it gets out of hand. [Written by MAL Rewrite]

For many girls in N-City, playing the popular social role-playing game Magical Girl Raising Project is as close as they could come to being a real magical girl. However, for some rare players, that dream can become a reality. One such girl is Koyuki Himekawa, who receives a notification one night that she has been selected to become a magical girl, her in-game avatar Snow White. As Koyuki and other chosen players in the city begin helping those in need, they all receive yet another notification: the admins have decided that they want to reduce the number of magical girls. Whoever collects the least amount of Magical Candies—which are awarded for their magical girl activities—in their competition each week will lose their powers. But when a real-world tragedy happens to the first player that drops out, they are shown the repercussions of losing their abilities. As more participants inevitably lose the competition and more twisted rules are added, the girls soon realize that their "contest" is actually a desperate fight for survival. [Written by MAL Rewrite]

A dying mob boss entrusts Lupin with a diamond that supposedly is the key to a vast treasure. But when Lupin is attacked by an assassin and saves a mysterious girl from trouble, it becomes clear that that there's more to this treasure then meets the eye... 

(Source: ANN)