The Original Sin (始まりの罪シリーズ) is currently made of 3 songs created by mothy. As the title suggests, this series takes place before the Seven Deadly Sins series and how they come to be.
This series tell the story of two children Hansel and Gretel. Go into the songs for more detail.
Although "Abandon Excerpts Moonlight" is set after "moonlit bear" mothy uploaded it first. "Chrono Story" was first included in mothy's "Evils Kingdom" album 4 months before he uploaded it on Nico Nico Douga with a PV.
Songs in the series: