Japan has a drug problem. Everywhere you look — from the creepy, teen-host-club pop of Sexy Zone to the soft-rock balladry of Ikimono Gakari — children are being exposed to music that has been made with no obvious influence from drugs whatsoever.

The music industry clearly likes it this way. The recent arrest of Aska from Chage and Aska, who pop fans might remember from history class at school, was followed as these things always are by the swift removal of all his records from CD shops, and by the immediate leap of the duo's hit "Say Yeah" to the top of the iTunes chart.

Aska, whose real name is Shigeaki Miyazaki, was allegedly found in possession of MDMA. However, the majority of drug arrests in Japan are still for methamphetamines. Japan has a long history with meth; the drug was invented by Japanese chemist Nagayoshi Nagai in 1893. It was used during the war by servicemen, factory workers who needed to remain alert through long shifts and by citizens to stave off hunger. It stuck around during postwar reconstruction under the brand name Philopon.