There is a custom in Japan that the first dream of the year is important to predict your luck of the year. Therefore what kind of dream you had between the evening of the New Year's day and the morning of 2 January is important.
There are three objects which can give you a luck during your sleep. If you had a dream about Mt.Fuji, Hawk or eggplant.
There are several theories why these objects are chosen. One of the major theories are that Ieyasu Tokugawa, who created the Tokugawa shogunate in 1603 loved these three objects. I hope you will wake up tomorrow morning and had a dream of Mt.Fuji, hawk or eggplant!