Mitsunori Imai, 60, who operates the Warabi-en bonsai garden here, was left speechless after he found many bonsai trees missing from his shelves on the morning of 12 December. "My mind went blank because of the shock," he said. The Nippon Bonsai Growers Cooperative had just called on members through the Line messaging app to take precautions following thefts at bonsai gardens around the country. Security cameras showed two men getting out of a vehicle in the rain, entering Warabi-en and walking out with bonsai trees in their hands. Imai said 24 pots, worth 7 million JPY (USD 49,000) in total, were snatched. "The thieves appear to have a certain level of knowledge about bonsai because they selected trees with a decent price," Imai said. However, he said the thieves don't appear to be professionals because more expensive trees remained untouched next to the stolen pots.