Less than five minutes into art group Maywa Denki's 25th anniversary show on April 14 at Square Ebara Hiratsuka Hall in Shinagawa, Novmichi Tosa, the lead member of the group, has the full house giggling — and they haven't even seen him yet.

It's pitch black and Tosa's grand entrance has proved to be less of the anticipated glorious bang than a few comically erratic "pops," accompanied by diminutive sparks of light.

A soft apologetic voice finds its way out of the darkness: "I think my battery has run out ..." And the giggles finally erupt into laughter.