Nestled in the serene landscapes of Kagawa Prefecture, Aoishima was founded by artisan Mr. Ninomiya, who specializes in the crafting of Aji stone, revered as the "Diamond of Granite" and exclusively quarried in Mure and Aji towns.

Aji stone, with origins dating back 80 to 90 million years, is renowned for its fine-grained structure and unparalleled durability. Known as "blue granite" for its bluish hue and scattered black mica, it has been esteemed throughout history.

The history of Aji stone began in the late Heian period, with significant milestones such as the construction of Takamatsu Castle in 1588 and the establishment of Yashima Tosho-gu Shrine in 1814. This 400-year-old tradition is carried on by skilled local artisans, whose exceptional craftsmanship is reflected in every piece they create.