Here's part of Wikipedia's entry on El Gamma Penumbra:
Early careerEl Gamma Penumbra was first founded in 2003 as a hip-hop boy group, competing in dance contests in their hometown. Before joining Pilipinas Got Talent, however, they changed their act thinking that there will be lesser chance of winning due to too many hip-hop dancers in the Philippines. Upon deciding to do shadow play, believing it is new and unique, they started practicing in a basketball court near their hometown using a tarpaulin and a halogen light as an improvisation.
They decided to produce an all-male group members, meaning females are not included, due to the "extreme body movements and contact required of their routines."
Thanks for the tip B.