Bon-chochin 盆提灯 are usually given to the bereaved family by their relatives on the first Obon festival after the death of ones in the family, and the Bon-chochin are to be placed in a room during (before/after) the Obon festival every year. Obon festivals are held July 13-16 in Tokyo and parts of eastern Japan, or August 13-16 in rural areas and most regions of western Japan. During the time of Obon, you will see many Bon-chochin sold at home improvement stores or at even super markets. Bon-chochin are beautifully designed, would be good as an interior lantern too.
Most of companies are closed for summer holiday during Obon festivals in 13-16 Auguest and the transportation system becomes extremely congested as people go back to their home town. It is strongly recommended to avoid traveling in Japan during the Obon season, if you are a tourist planning to visit Japan in August.