Hozuki is physalis alkekengi in English. It has also other names such as Bladder cherry, Chinese lantern and Winter cherry.
At this time of the year, hozuki is used as part of the Bon Festival as offerings to guide the souls of the deceased. (Bon Festival is Buddhist event when the deceased spirits are believed to return to their home.)
In Japan, a hozuki fruit was used as a fun, especially for girls. Just yesterday my friend showed me how to do it. She made a funny sound by hollowing an empty fruit in her mouth.
But it took a lot of perseverance to take out seeds. It’s not my kind.