More than half of junior high and high school students in the Tokyo metropolitan area think they can obtain quasi-legal "kiken" (dangerous) drugs, according to a survey of 3,858 students by a Tokyo-based nonprofit group.

Police have recently stepped up crackdowns on the quasi-legal drugs, by raiding shops selling them and charging drivers under their influence. But the drugs are increasingly spreading among the young.

Last July, the Yamagata Prefectural Police arrested a 15-year-old girl and a 16-year-old boy for alleged possession of the drugs, which are part of a group of drugs that have stimulant or hallucinatory effects but include chemicals not clearly banned by law.

Nihon Yakubutsu Taisaku Kyokai (The Association to Tackle Drug Problems in Japan) conducted a survey of junior high and high school students in Tokyo, Kanagawa, Chiba and Saitama prefectures between September and December last year.

It found that 28.4 percent of the respondents said they "think they can obtain the drugs easily," while another 24.9 percent replied the drugs "might take some effort but they are accessible."

Twenty-one students, or 0.5 percent of the total, also replied they have been suggested to try the drugs, while another 1.6 percent said they have seen or heard their friends and acquaintances inhaling the substances.

The association warns that, while many shops selling the drugs over the counter have been shut down, the drugs are still available on the Internet and through catalogs, and thus students become familiar with them through those channels.