diff --git a/playshogi-library-shogi-files/src/main/java/com/playshogi/library/shogi/files/BatchDiagramGenerator.java b/playshogi-library-shogi-files/src/main/java/com/playshogi/library/shogi/files/BatchDiagramGenerator.java
index 234407f3..e5689682 100644
--- a/playshogi-library-shogi-files/src/main/java/com/playshogi/library/shogi/files/BatchDiagramGenerator.java
+++ b/playshogi-library-shogi-files/src/main/java/com/playshogi/library/shogi/files/BatchDiagramGenerator.java
@@ -9,27 +9,29 @@
 import java.nio.file.Files;
 import java.util.stream.Stream;
 
+// generates many diagrams at once from one file into SVGs
 public class BatchDiagramGenerator {
 
     public static void main(String[] args) throws IOException {
+        // takes file with many sfens, one in each line
         File file = new File("C:\\Users\\Oneye\\Documents\\SFEN for book\\sfen.txt");
         try (BufferedReader bufferedReader = new BufferedReader(new FileReader(file))) {
-            int counter = 0;
+            int exportedFileEnumeration = 0; // saves in files with increasing numbers in its name
             for (String line = bufferedReader.readLine(); line != null; line = bufferedReader.readLine()) {
                 System.out.println(line);
                 try {
-                    ShogiPosition shogiPosition = SfenConverter.fromSFEN(line);
-                    String svg = SVGConverter.toSVG(shogiPosition);
+                    ShogiPosition shogiPosition = SfenConverter.fromSFEN(line); // get position
+                    String svg = SVGConverter.toSVG(shogiPosition); // convert into SVG then save it
                     System.out.println(svg);
-                    counter++;
-                    writeToFile(svg, counter);
+                    exportedFileEnumeration++;
+                    writeToFile(svg, exportedFileEnumeration);
                 }catch (Exception ignored){}
             }
         }
     }
 
-    private static void writeToFile(final String svg, final int counter) throws IOException {
-        File file = new File("C:\\Users\\Oneye\\Documents\\SFEN for book\\diagrams\\Diagram"+counter+".svg");
+    private static void writeToFile(final String svg, final int fileSuffix) throws IOException {
+        File file = new File("C:\\Users\\Oneye\\Documents\\SFEN for book\\diagrams\\Diagram"+fileSuffix+".svg");
 
         FileWriter wr = new FileWriter(file);
         wr.write(svg);
diff --git a/playshogi-library-shogi/src/main/java/com/playshogi/library/shogi/models/formats/svg/SVGConverter.java b/playshogi-library-shogi/src/main/java/com/playshogi/library/shogi/models/formats/svg/SVGConverter.java
index 986c6bc6..4e875d27 100644
--- a/playshogi-library-shogi/src/main/java/com/playshogi/library/shogi/models/formats/svg/SVGConverter.java
+++ b/playshogi-library-shogi/src/main/java/com/playshogi/library/shogi/models/formats/svg/SVGConverter.java
@@ -40,6 +40,7 @@ public static String toSVG(final ReadOnlyShogiPosition position) {
         appendBoard(svg);
         appendPieces(position, svg);
 
+        // todo "all the remaining pieces in hand" for tsumeshogi
         appendBlackPiecesInHand(position, svg);
         appendWhitePiecesInHand(position, svg);
 
@@ -161,7 +162,7 @@ private static void appendBlackPiecesInHand(final ReadOnlyShogiPosition position
 
         if(hand.length() == 1) {
             //hand.append("なし");
-            hand.append("Nothing");
+            hand.append("-"); // nothing in hand
         }
 
         int x = MARGIN_LEFT + 9 * SQUARE_WIDTH + 10;
@@ -177,7 +178,7 @@ private static void appendBlackPiecesInHand(final ReadOnlyShogiPosition position
                     .append("</tspan></text>");
         }
 
-        svg.append("</g>\n"); // black hand
+        svg.append("</g>\n"); // end of the black-hand
     }
 
 
@@ -195,7 +196,8 @@ private static void appendWhitePiecesInHand(final ReadOnlyShogiPosition position
         }
 
         if(hand.length() == 1) {
-            hand.append("なし");
+            //hand.append("なし");
+            hand.append("-"); // nothing in hand
         }
 
         int x = - (MARGIN_LEFT - 10);
@@ -211,7 +213,7 @@ private static void appendWhitePiecesInHand(final ReadOnlyShogiPosition position
                     .append("</tspan></text>");
         }
 
-        svg.append("</g>\n"); // black hand
+        svg.append("</g>\n"); // end of the white-hand
     }