Prosecutors demanded an 18-month prison term Friday for actor and singer Manabu Oshio, who pleaded guilty to using the illegal synthetic drug MDMA in August.

Oshio, 31, admitted at the Tokyo District Court to taking the illegal drugs, also known as Ecstacy, on Aug. 2 at an apartment in Tokyo's Roppongi district with a woman who apparently subsequently died from them. He is charged with violating the narcotics and psychotropics control law.

"I will never repeat the same mistake again. I have betrayed many people, my family, friends and fans, and I am very sorry," Oshio said at his one-day trial session.