Greenery Day, a national holiday in Japan meant to appreciate nature, is observed every May 4th. From its establishment in 1989 until 2007, however, it was celebrated every April 29th. In 2005, as part of a Greenery Day celebration, a bamboo shoot digging event was held in Kagawa Prefecture’s Goshikidai Forest. (Yes, this is a thing. Many people in Asia like boiling and eating the shoots.)

Some 60 people showed up to participate, including five-year-old Yuki Onishi and her mother and eight-year-old sister. The event started at 1 PM, and Yuki jumped with joy when she found her first shoot about a half-hour later. She told her mother that she was going to find another one, and then walked away to continue her search.

20 minutes after Yuki ran off, her mother looked at where all the other diggers were and suddenly realized that her daughter was missing. After a search by themselves turned up nothing, Yuki’s family called the police at 3 PM. When the police still couldn’t find a single trace of the girl, firefighters were brought in to assist the search at 5 PM. Although the authorities combed the area for the next six hours, they still weren’t able to find anything, not even a shoe or the hat Yuki was wearing.

Eventually, over 3,000 people assisted in the case, but not a single one of them was able to find any clues. The forest where Yuki disappeared and a near-by pond seemed to turn up nothing. When a police dog was brought in to follow Yuki’s scent, it suddenly stopped in its tracks in the middle of the forest.  Four other dogs were made to follow the scent the next day, but they led police to the same exact spot.

This is probably the most troubling part of the case. How could somebody seemingly just vanish into thin air? A few internet sleuths have suggested that Yuki was carried off by an eagle or some other large bird. I’m sure we’ve all heard stories about eagles swooping down on a baby or toddler and grabbing them, but those are really just tall tales. According to biologist Ron Clarke, the most an eagle can carry without any difficulty is four or five pounds. At 34 pounds, Yuki would have been way too heavy for an eagle’s carrying capacity.

The other, and I’d say more plausible, theory is that Yuki was lured away and snatched up by somebody who was just passing through the forest. While nobody particularly suspicious was noticed by the diggers, some of them did see a man walking through the area with a backpack large enough to hold a child of Yuki’s size. This man has never been identified, although he might have been a camper or hiker. 

At the time of her disappearance, Yuki Onishi weighed 34 pounds (15.5 kg) and stood at 3 feet, 5 inches (106 cm). She was wearing a pink hat, a long-sleeved shirt with a red and orange pattern, white gloves, long blue pants, and pink shoes. She was 5-years-old, and as of the time of this writing, would now be 15-16. A website set up for Yuki, which Japanese-speakers can access here, offers a printable flyer and contact information for anybody who might be able to help.

Be sure to check out more offbeat stories of Japanese crime, folklore, and history in my e-book, 20 Unsolved Mysteries of Japan, available on Amazon for Kindle.