Epigraph of the Closed Curve

Steins;Gate - Epigraph of the Closed Curve (平時曲線のエピグラフ - Heijikyokusen no Epigraph?  ) is a side story occuring during the winter of 2010 in the Beta Attractor Field around World line divergences 1.129848 and 1.130205%.

It has been published in light novel, drama cd, and manga forms.