A female singing duo, who for years have been performing live concerts at Japanese prisons and encouraging inmates to reform their ways to successfully reenter society, have come quite a way since their days of nervousness onstage.

At an event earlier this year, the group known as Paix2 (pronounced pay-pay) crooned for an audience of nearly 900 clean-shaven men, who sat eerily quiet as they watched the women perform at Yokohama Prison.

Megumi Ikatsu, 40, and Manami Kitao, 38, known in Japan's correctional circles as "prison idols," sang nine songs during the 75-minute morning show in the prison grounds, receiving warm applause from the men clad in light green work uniforms.