Muji has more than 500 shops in 25 countries around the world. Cavalier Woolscourers chief executive Nigel Hales said Muji wanted to gain a better understanding of the New Zealand wool supply chain.
A key concern was traceability from the products' origins through to the finished goods.
Mr Hales said he was impressed with Muji when he visited one of its shops in Central Tokyo about a month ago. It was displaying very high-quality garments made from New Zealand wool and he was pleased to see the amount of pure wool and natural fibres used in its products.
Muji shops sell a range of items, including homeware, cosmetics, electronics and food, as well as clothing.
The Timaru plant was chosen to host the Japanese delegation because it was well set up to receive wool directly from farms and to process the high-value Merino clip, he said.
Cavalier Woolscours chief operating officer Tony Cunningham said he was keen to show the visitors how New Zealand wool could be traced from the farm through to early processing.
The Muji people could see that the wool was grown in the South Island's central high country and could still be identified after having gone through the supply chain.
The guests were invited to help sort the wool and see it being washed. That would give them first-hand experience of the wool that would end up on their shop shelves.
''This was the first visit to New Zealand by Muji and they were delighted to see the high level of professionalism at the Cavalier Woolscourers site,'' Mr Cunningham said.
The party included Motohiro and Co Ltd president Tetsuya Motohiro, from Osaka, and Fumihide Satomura, of Ryohin Keikaku, Tokyo, plus New Zealand wool exporters Peter Christiansen, from Furhmann Ltd, and Schneider NZ Ltd's Helen Cameron.