diff --git a/README.md b/README.md
index 2c6dae5..4c58153 100644
--- a/README.md
+++ b/README.md
@@ -5,12 +5,13 @@ A library for handling exceptions with reasons.
 In Java programming, it is cumbersome to implement a separate exception class for each exception case.
 However, trying to handle multiple exception cases with a single exception class makes it difficult to distinguish between them.
 
-The exception class `Exc` provided by this library solves this problem by accepting a `Record` object that represents the reason for the exception.
+The exception class `Exc` provided by this library solves this problem by accepting an object that represents the reason for the exception.
+Typically, the type of this reason object is `Record`.
 Since a `Record` object can have any fields, it can store information about the situation at the time the exception occurred.
-The type of the `Record` object can be determined and cast using a switch statement, making it easy to write handling logic for each exception case.
+The type of the reason can be determined and cast using a switch statement, making it easy to write handling logic for each exception case.
 
 Optionally, when an `Exc` object is instantiated, pre-registered exception handlers can receive notifications either synchronously or asynchronously.
-However, to enable this feature, you must specify the system property `-Dgithub.sttk.errs.notify=true` at program startup.
+However, to enable this feature, the system property `-Dgithub.sttk.errs.notify=true` must be specified at program startup.
 
 ## Install
 
diff --git a/src/main/java/com/github/sttk/errs/Exc.java b/src/main/java/com/github/sttk/errs/Exc.java
index 4698fc6..9eb5ee9 100644
--- a/src/main/java/com/github/sttk/errs/Exc.java
+++ b/src/main/java/com/github/sttk/errs/Exc.java
@@ -18,8 +18,9 @@
 /**
  * Is the exception class with a reason.
  * <p>
- * This class has a record field which indicates a reason for this exception. The class name of the reason record
- * represents the type of reason, and the fields of the reason record hold the situation where the exception occurred.
+ * This class has a field which indicates a reason for this exception. Typically the type of this field is
+ * {@link Record}. In this case, the class name of this record represents the reason, and the fields of the record hold
+ * the situation where the exception occurred.
  * <p>
  * Optionally, this exception class can notify its instance creation to pre-registered exception handlers. This
  * notification feature can be enabled by specifying the system property {@code -Dgithub.sttk.errs.notify=true} when the
@@ -44,18 +45,18 @@ public final class Exc extends Exception {
     private static final long serialVersionUID = 260427082865587554L;
 
     /** The reason for this exception. */
-    private transient Record reason;
+    private transient Object reason;
 
     /** The stack trace for the location of occurrence. */
     private StackTraceElement trace;
 
     /**
-     * Is the constructor which takes a {@link Record} object indicating the reason for this exception.
+     * Is the constructor which takes an object indicating the reason for this exception.
      *
      * @param reason
      *            A reason for this exception.
      */
-    public Exc(final Record reason) {
+    public Exc(final Object reason) {
         if (reason == null) {
             throw new IllegalArgumentException("reason is null");
         }
@@ -67,8 +68,8 @@ public Exc(final Record reason) {
     }
 
     /**
-     * Is the constructor which takes a {@link Record} object indicating the reason and {@link Throwable} object
-     * indicating the cause for this exception.
+     * Is the constructor which takes an object indicating the reason and {@link Throwable} object indicating the cause
+     * for this exception.
      *
      * @param reason
      *            A reason for this exception.
@@ -76,7 +77,7 @@ public Exc(final Record reason) {
      *            A cause for this exception.
      */
     @SuppressWarnings("this-escape")
-    public Exc(final Record reason, final Throwable cause) {
+    public Exc(final Object reason, final Throwable cause) {
         super(cause);
 
         if (reason == null) {
@@ -94,7 +95,7 @@ public Exc(final Record reason, final Throwable cause) {
      *
      * @return The reason for this exception.
      */
-    public Record getReason() {
+    public Object getReason() {
         return this.reason;
     }
 
@@ -105,13 +106,7 @@ public Record getReason() {
      */
     @Override
     public String getMessage() {
-        var rsn = this.reason.toString();
-        var rname = this.reason.getClass().getSimpleName();
-        rsn = rsn.substring(rname.length() + 1, rsn.length() - 1);
-
-        var buf = new StringBuilder(this.reason.getClass().getName());
-        buf.append(" { ").append(rsn).append(" }");
-        return buf.toString();
+        return reason.toString();
     }
 
     /**
@@ -123,7 +118,7 @@ public String getMessage() {
     @Override
     public String toString() {
         var buf = new StringBuilder(getClass().getName());
-        buf.append(" { reason = ").append(getMessage());
+        buf.append(" { reason = ").append(reason.getClass().getName()).append(" ").append(reason.toString());
         buf.append(", file = ").append(this.trace.getFileName());
         buf.append(", line = ").append(this.trace.getLineNumber());
         if (getCause() != null) {
@@ -166,8 +161,8 @@ public RuntimeException toRuntimeException() {
     /**
      * Writes a serial data of this exception to a stream.
      * <p>
-     * Since a {@link Record} object is not necessarily serializable, this method will throw a
-     * {@link NotSerializableException} if the {@code reason} field does not inherit {@link Serializable}.
+     * Since a reason object is not necessarily serializable, this method will throw a {@link NotSerializableException}
+     * if the {@code reason} field does not inherit {@link Serializable}.
      *
      * @param out
      *            An {@link ObjectOutputStream} to which data is written.
@@ -185,8 +180,7 @@ private void writeObject(ObjectOutputStream out) throws IOException {
 
     /**
      * Reconstitutes the {@code Exc} instance from a stream and initialize the reason and cause properties when
-     * deserializing. If the reason by deserialization is null or invalid, this method throws
-     * {@link InvalidObjectException}.
+     * deserializing. If the reason by deserialization is null, this method throws {@link InvalidObjectException}.
      *
      * @param in
      *            An {@link ObjectInputStream} from which data is read.
@@ -198,7 +192,7 @@ private void writeObject(ObjectOutputStream out) throws IOException {
      */
     private void readObject(ObjectInputStream in) throws ClassNotFoundException, IOException {
         in.defaultReadObject();
-        this.reason = Record.class.cast(in.readObject());
+        this.reason = in.readObject();
 
         if (this.reason == null) {
             throw new InvalidObjectException("reason is null or invalid.");
diff --git a/src/test/java/com/github/sttk/errs/ExcTest.java b/src/test/java/com/github/sttk/errs/ExcTest.java
index 609bb99..6718740 100644
--- a/src/test/java/com/github/sttk/errs/ExcTest.java
+++ b/src/test/java/com/github/sttk/errs/ExcTest.java
@@ -2,6 +2,7 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.fail;
+import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 
@@ -31,7 +32,7 @@ record SerializableReason(String name, int index, int min, int max) implements S
     @Nested
     class TestConstructor {
         @Test
-        void with_reason() {
+        void with_Record_reason() {
             var exc = new Exc(new IndexOutOfRange("data", 4, 0, 3));
             var reason = IndexOutOfRange.class.cast(exc.getReason());
             assertThat(reason.name()).isEqualTo("data");
@@ -43,6 +44,28 @@ void with_reason() {
             // exc.printStackTrace();
         }
 
+        @Test
+        void with_enum_reason() {
+            enum Reasons {
+                FailToDoSomething,
+            }
+
+            var exc = new Exc(Reasons.FailToDoSomething);
+            var reason = Reasons.class.cast(exc.getReason());
+            assertThat(reason.name()).isEqualTo("FailToDoSomething");
+            assertThat(exc.getCause()).isNull();
+
+            // exc.printStackTrace();
+        }
+
+        @Test
+        void with_String_reason() {
+            var exc = new Exc("FailToDoSomething");
+            var reason = String.class.cast(exc.getReason());
+            assertThat(reason).isEqualTo("FailToDoSomething");
+            assertThat(exc.getCause()).isNull();
+        }
+
         @Test
         void with_reason_but_reason_is_null() {
             try {
@@ -104,7 +127,7 @@ void identify_reason_with_instanceOf() {
         }
 
         @Test
-        void identify_reason_with_switch_expression() {
+        void identify_Record_reason_with_switch_expression() {
             var exc = new Exc(new IndexOutOfRange("data", 4, 0, 3));
             switch (exc.getReason()) {
                 case IndexOutOfRange reason -> {
@@ -116,6 +139,24 @@ void identify_reason_with_switch_expression() {
                 default -> fail();
             }
         }
+
+        @Test
+        void identify_Enum_reason_with_switch_expression() {
+            enum Reasons {
+                FailToDoSomething, InvalidValue,
+            }
+
+            var exc = new Exc(Reasons.FailToDoSomething);
+
+            var s = switch (exc.getReason()) {
+                case Reasons enm -> switch (enm) {
+                    case FailToDoSomething -> "fail to do something";
+                    case InvalidValue -> "invalid value";
+                };
+                default -> "unknown";
+            };
+            assertThat(s).isEqualTo("fail to do something");
+        }
     }
 
     @Nested
@@ -151,7 +192,7 @@ void getFile() {
         @Test
         void getLine() {
             var exc = new Exc(new IndexOutOfRange("data", 4, 0, 3));
-            assertThat(exc.getLine()).isEqualTo(153);
+            assertThat(exc.getLine()).isEqualTo(194);
         }
     }
 
@@ -160,16 +201,14 @@ class TestGetMessage {
         @Test
         void with_cause() {
             var exc = new Exc(new IndexOutOfRange("data", 4, 0, 3));
-            assertThat(exc.getMessage())
-                    .isEqualTo("com.github.sttk.errs.ExcTest$IndexOutOfRange { name=data, index=4, min=0, max=3 }");
+            assertThat(exc.getMessage()).isEqualTo("IndexOutOfRange[name=data, index=4, min=0, max=3]");
         }
 
         @Test
         void with_no_cause() {
             var cause = new IndexOutOfBoundsException(4);
             var exc = new Exc(new IndexOutOfRange("data", 4, 0, 3), cause);
-            assertThat(exc.getMessage())
-                    .isEqualTo("com.github.sttk.errs.ExcTest$IndexOutOfRange { name=data, index=4, min=0, max=3 }");
+            assertThat(exc.getMessage()).isEqualTo("IndexOutOfRange[name=data, index=4, min=0, max=3]");
         }
     }
 
@@ -179,7 +218,7 @@ class TestToString {
         void with_reason() {
             var exc = new Exc(new IndexOutOfRange("data", 4, 0, 3));
             assertThat(exc.toString()).isEqualTo(
-                    "com.github.sttk.errs.Exc { reason = com.github.sttk.errs.ExcTest$IndexOutOfRange { name=data, index=4, min=0, max=3 }, file = ExcTest.java, line = 180 }");
+                    "com.github.sttk.errs.Exc { reason = com.github.sttk.errs.ExcTest$IndexOutOfRange IndexOutOfRange[name=data, index=4, min=0, max=3], file = ExcTest.java, line = 219 }");
         }
 
         @Test
@@ -187,7 +226,7 @@ void with_reason_and_cause() {
             var cause = new IndexOutOfBoundsException(4);
             var exc = new Exc(new IndexOutOfRange("data", 4, 0, 3), cause);
             assertThat(exc.toString()).isEqualTo(
-                    "com.github.sttk.errs.Exc { reason = com.github.sttk.errs.ExcTest$IndexOutOfRange { name=data, index=4, min=0, max=3 }, file = ExcTest.java, line = 188, cause = java.lang.IndexOutOfBoundsException: Index out of range: 4 }");
+                    "com.github.sttk.errs.Exc { reason = com.github.sttk.errs.ExcTest$IndexOutOfRange IndexOutOfRange[name=data, index=4, min=0, max=3], file = ExcTest.java, line = 227, cause = java.lang.IndexOutOfBoundsException: Index out of range: 4 }");
         }
     }
 
@@ -197,8 +236,7 @@ class TestToRuntimeException {
         void getMessage() {
             var exc = new Exc(new IndexOutOfRange("data", 4, 0, 3));
             var rtExc = exc.toRuntimeException();
-            assertThat(rtExc.getMessage())
-                    .isEqualTo("com.github.sttk.errs.ExcTest$IndexOutOfRange { name=data, index=4, min=0, max=3 }");
+            assertThat(rtExc.getMessage()).isEqualTo("IndexOutOfRange[name=data, index=4, min=0, max=3]");
         }
 
         @Test