Popular singer-songwriter Noriyuki Makihara pleaded guilty Tuesday to possession of illegal drugs in the first hearing of his trial at the Tokyo District Court, with prosecutors seeking a two-year prison term.

Prosecutors said the 51-year-old had been using the liquid inhalant isobutyl nitrite, a type of "popper" commonly known in Japan as "Rush," for about 30 years as well as an illegal stimulant drug since at least 1999, even after he was found guilty of a drug charge the same year.

"I am sorry for all my fans," Makihara said, adding that he had not taken any illicit substances for several years and had cut ties with his former dealer. "I feel happy enough even without using drugs."