When Naoki Itasaka, owner of an interior finishing company, heard his alma mater was likely to be demolished after being closed down, he came up with an idea for a new business that would, instead, make good use of the existing campus — sturgeon farming to produce caviar.

So in January, the 45-year-old owner of Takamatsu-based Daikyo Kenko purchased the land and buildings of the former junior high school in Higashikagawa, Kagawa Prefecture, for ¥10 million. With the help of a company with expertise and technology in sturgeon aquaculture, the new business was launched in May.

Four cylindrical water tanks, each approximately 3 meters in diameter, sit inside what used to be the school gymnasium. Despite the tanks' gigantic size, the sturgeons, ranging from 10 cm to 50 cm long, still looked a bit cramped swimming inside them.