This is an item of stationery (paper or writing goods), or other small merchandise such as good-luck charms, mascot straps, et cetera.
Vocaloid mascot Miku Hatsune has a leek--and she knows how to use it! This wackily-designed figure of Miku, complete with her favorite veggie, stands on a small music box (combined, both are about 12cm tall). The music box plays the unforgettable "Ievan Polkka" (by "unforgettable," we mean "complete and total earworm"). This game-prize item by Sega is a really unique collectible, and the perfect gift for any Miku fan! (Check out the "normal" version, too, linked below!)