This is a Japanese-language illustration (art) book.
From Kadokawa comes this hardcover artbook featuring Noiji Itou's illustrations of characters from "The Melancholy of Haruhi Suzumiya"! This all-color book gathers 70 gorgeous full-page illustrations that include ones previously published in The Sneaker and Newtype magazines, limited-edition DVD jackets, and more. There's also an illustration index section where the famous illustrator provided her comments on each piece. All text is in Japanese.