Why did Skyward Sword get four Japanese guides on one day?

Skyward Sword was the Wii's big Christmas game of 2011, and Japan's guide publishers treated its guide launch like a starting gun. All four licensed Japanese guides were published on the same day, December 20, 2011, about a month after the game itself.

What separates them is bulk. Nintendo DREAM's guide runs 480 pages, Dengeki's Complete guide 367, Enterbrain's Perfect guide 255 and Shogakukan's Wonder Life Special book 239. Same game, same day, four different answers to the question of how much book a player needs, from the Wonder Life player's guide to Nintendo DREAM's near encyclopedia.

The covers split from the West too. Prima's American guide is a gold foil design; three of the Japanese covers are confirmed different art, with Nintendo DREAM using Link raising his sword against a light blue sky, Dengeki putting Link on the red Loftwing, and Shogakukan using the painterly key visual with the faces of Ghirahim and Fi flanking Link.

One gap is recorded honestly: the ISBNs of the four Wii books have not been verified for this census, so they are not printed here. The dates, publishers and page counts are the documented facts.