Yuuji and the Flame Haze Shana have thwarted several of the Bal Masque’s evil schemes, but the lives of a Flame Haze and the holder of the Reiji Maigo are never simple. While rifling through a pile of objects, Yuuji finds what appears to be a telescope; but after looking through it at Shana, an unfortunate side effect occurs: they switch bodies! Now inhabiting the flesh of the other, the two must stick it out until they can change back. What other adventures await the supernatural pair?
Following the war against Albion, Saito has returned to the Tristain Academy and is becoming increasingly closer to Louise. However, their newfound tranquillity is shattered when one day, the runes on the back of Saito’s hand disappear. Saito is now free from being Louise’s familiar, but not from her ‘explosive’ temper. Nevertheless, Saito refuses to leave Louise’s side and pledges to help her find a way to renew their contract and regain his powers. Soon, while on a mission to find the elf that revived Saito during the final battle against Albion, the duo encounters the mysterious Sheffield: a familiar of another void magic user. Why is Sheffield pursuing the pair and what plans does her master have for them?
Oh yea. They're the same since the major characters are almost the same, also the relationship between these characters. (also their voice actors!) But Shakugan No Shana S and all other installments of Shakugan No Shana has more intense action scenes.. Yes.yes.
So.. watch both! hehe..
Both animes have the same basic elements. They are both very well done animes and if you liked/watched either Zero no Tsukaima or even Shakugan no Shana, you will enjoy watching the other.
And if you haven't watched either I highly suggest that you do, especially if you enjoy a romance anime with action, magic, and cute spunky tempermental heroines.