Zero no Tsukaima (Zero's Familiar) is pretty amusing. It's not likely to crack my Top Four List like Suzumiya Haruhi no Yuuutsu (which was astoundingly good—nearly Azumanga Daioh good), but it's definitely one of summer shows worth watching this season.
Zero no Tsukaima (which I can't stop calling Hermione ZERO) is about a second-year magic school student at a rather Harry Potter-ish academy who inadvertantly summons a computer nerd from Tokyo as her familiar. Rather than being a high-speed honor student-type girl like Hermione Granger, ol' Louise is a consistent failure as a mage, which accounts for her "Zero Louise" nickname. Louise carries the show with the power of tsundere (and with the power of zettai ryouiki, some may argue). Refreshingly, Saito, Louise's reluctant familiar, is considerably more assertive than the typical male protagonist wimp one usually finds in anime like this. He stands up for himself in episode two, and defiantly takes his lumps in stride.
It is unclear whether or not this is intentional, but Saito's episode-two injuries appear limited to his right side; his left side seems relatively uninjured. Perhaps it has something to do with the myserious runes on the back of his left hand. The runes manifested after Louise and Saito sealed their magician/familiar contract, but they seem to have special significance to the academy's Dumbledore/Gandalf correlate.
The runes also attract the attention of Ms. Longueville. I hope I'm not ruining the show for anyone, but it seems pretty clear to me after seeing her treatment and subsequent reaction in episode two that she is the cloaked green-haired antagonist seen in the OP. I mean, c'mon.
There's also something unusual about Zero no Tsukaima's version of YUKI.N>.
Zero's Familiar is exected to run 12 or 13 episodes and should remain fairly entertaining thanks to its lively cast of characters. It also shares many of the same voice actors as last autumn's Shakugan no Shana, so it's also amusing in the VanDread:Stratos 4 sort of way. It also has Yui Horie sweetness and J.C. Staff designs to seal the deal, ensuring that Zero no Tsukaima will reign as this season's tsundere romantic comedy. It's much better than the wretched Tsuyokiss which is going to need a 180-degree turn for the better, and fast.