From the video description, because they said it way better than I ever could:
“A unique production, The Little Lion Men’s entire musical score is composed of the songs written by the newly successful band, Mumford and Sons. The story takes place in Victorian London, and the plot is driven by a clash of the classes. It is a story of brave men versus corruption, of those who have little versus those who have everything, and of doing what is right versus doing what is easy.
Completely student written, directed, choreographed, and performed, The Little Lion Men ran the first week in November, 2011, in an old warehouse renovated and transfigured into a theatrical environment. Due to an overwhelming response, the cast performed an encore performance the following weekend. All proceeds were donated to New Horizons, a home for children who have been removed from their legal guardians due to physical and mental abuse. In the end, the kids of New Horizons received over $3600 worth of Christmas presents, delivered by the cast and crew to the annual New Horizons Christmas party.”