TOKOROZAWA, Saitama Pref. -- When Eiko Kotani, 47, moved with her husband to the suburbs of Tokorozawa's Shimotomi district 19 years ago, she thought the forest sprawling behind their new home would make a perfect playground for their young son and future children. It did, at least for a while.
"The kids enjoyed climbing trees, picking mushrooms and having barbecued foods," Kotani recalls. "We also made fires, grilling sweet potatoes and chestnuts just about every evening in the fall and winter."
But things changed in February 1991, when ash started piling up on the windshield of the family car, and black smoke and a sharp odor began to foul the forest, locally known as "Kunugi-yama" ("Oak Hill").