diff --git a/src/main/java/cit/PureATN/PPPath.java b/src/main/java/cit/PureATN/PPPath.java
index 88a2698..914c751 100644
--- a/src/main/java/cit/PureATN/PPPath.java
+++ b/src/main/java/cit/PureATN/PPPath.java
@@ -5,6 +5,9 @@
 
 import org.piccolo2d.nodes.PPath;
 
+/**
+ * 以前のPiccolo PPathとの互換性をとるためのクラス
+ */
 public class PPPath extends PPath.Double {
     public PPPath(){
         super(new Path2D.Float());