diff --git a/src/GuardCore/Guard.cs b/src/GuardCore/Guard.cs
index e1e88fb..c9f45f9 100644
--- a/src/GuardCore/Guard.cs
+++ b/src/GuardCore/Guard.cs
@@ -1,4 +1,4 @@
-namespace GuardCore;
+namespace Takayama.GuardCore;
 
 public static class Guard
 {
diff --git a/src/GuardCore/GuardCore.csproj b/src/GuardCore/GuardCore.csproj
index 8c035af..06d1ae1 100644
--- a/src/GuardCore/GuardCore.csproj
+++ b/src/GuardCore/GuardCore.csproj
@@ -5,8 +5,8 @@
 
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;netstandard2.1;net8.0;net9.0;net10.0</TargetFrameworks>
-    <RootNamespace>GuardCore</RootNamespace>
-    <AssemblyName>GuardCore</AssemblyName>
+    <RootNamespace>Takayama.GuardCore</RootNamespace>
+    <AssemblyName>Takayama.GuardCore</AssemblyName>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <!-- 1701/1702: Summary references, 0436: PolySharp source conflicts, 9124: Ref struct checks -->
diff --git a/src/GuardCore/Result.cs b/src/GuardCore/Result.cs
index 69f9fe4..04649fd 100644
--- a/src/GuardCore/Result.cs
+++ b/src/GuardCore/Result.cs
@@ -1,4 +1,4 @@
-namespace GuardCore;
+namespace Takayama.GuardCore;
 
 public readonly struct Result<TValue, TError> where TError : Enum
 {
diff --git a/src/GuardCore/ResultExtensions.cs b/src/GuardCore/ResultExtensions.cs
index 9fad7d2..19f2dd7 100644
--- a/src/GuardCore/ResultExtensions.cs
+++ b/src/GuardCore/ResultExtensions.cs
@@ -1,4 +1,4 @@
-namespace GuardCore;
+namespace Takayama.GuardCore;
 
 /// <summary>
 /// Transforms the inner error type if the result is a failure.
diff --git a/src/GuardCore/Unit.cs b/src/GuardCore/Unit.cs
index 3bc9bd3..fad2abb 100644
--- a/src/GuardCore/Unit.cs
+++ b/src/GuardCore/Unit.cs
@@ -1,4 +1,4 @@
-namespace GuardCore
+namespace Takayama.GuardCore
 {
     /// <summary>
     /// Represents a type with only one value. 
diff --git a/tests/GuardCore.Tests/EnsureTests.cs b/tests/GuardCore.Tests/EnsureTests.cs
index 68c7740..8dd5d17 100644
--- a/tests/GuardCore.Tests/EnsureTests.cs
+++ b/tests/GuardCore.Tests/EnsureTests.cs
@@ -1,4 +1,4 @@
-namespace GuardCore.Tests;
+namespace Takayama.GuardCore.Tests;
 
 public class EnsureTests
 {
@@ -31,4 +31,4 @@ public void Ensure_WhenConditionPasses_ShouldNotThrow()
     {
         Should.NotThrow(() => Guard.Ensure(true, "This should never throw"));
     }
-}
\ No newline at end of file
+}
diff --git a/tests/GuardCore.Tests/GuardCore.Tests.csproj b/tests/GuardCore.Tests/GuardCore.Tests.csproj
index b2b4bf4..5c74009 100644
--- a/tests/GuardCore.Tests/GuardCore.Tests.csproj
+++ b/tests/GuardCore.Tests/GuardCore.Tests.csproj
@@ -42,7 +42,7 @@
   <ItemGroup>
     <Using Include="Xunit" />
     <Using Include="Shouldly" />
-    <Using Include="GuardCore" />
+    <Using Include="Takayama.GuardCore" />
     <Using Include="System.Runtime.CompilerServices" />
   </ItemGroup>
 
diff --git a/tests/GuardCore.Tests/GuardStateLogicTests.cs b/tests/GuardCore.Tests/GuardStateLogicTests.cs
index fbbbb6e..88e244b 100644
--- a/tests/GuardCore.Tests/GuardStateLogicTests.cs
+++ b/tests/GuardCore.Tests/GuardStateLogicTests.cs
@@ -1,4 +1,4 @@
-namespace GuardCore.Tests;
+namespace Takayama.GuardCore.Tests;
 
 public class GuardStateLogicTests
 {
@@ -48,4 +48,4 @@ public void Deconstruct_ShouldUnpackInternalStateFieldsCorrectly()
         isSuccess.ShouldBeFalse();
         error.ShouldBe(TestError.InvalidId);
     }
-}
\ No newline at end of file
+}
diff --git a/tests/GuardCore.Tests/GuardStateTerminalTests.cs b/tests/GuardCore.Tests/GuardStateTerminalTests.cs
index 68db79d..921c9a5 100644
--- a/tests/GuardCore.Tests/GuardStateTerminalTests.cs
+++ b/tests/GuardCore.Tests/GuardStateTerminalTests.cs
@@ -1,4 +1,4 @@
-namespace GuardCore.Tests;
+namespace Takayama.GuardCore.Tests;
 
 public class GuardStateTerminalTests
 {
@@ -59,4 +59,4 @@ public void ToResult_WhenSuccess_ShouldReturnUnitSuccessResult()
         result.IsSuccess.ShouldBeTrue();
         result.Value.ShouldBe(Unit.Default);
     }
-}
\ No newline at end of file
+}
diff --git a/tests/GuardCore.Tests/ResultExtensionsTests.cs b/tests/GuardCore.Tests/ResultExtensionsTests.cs
index ed6c461..ddc97eb 100644
--- a/tests/GuardCore.Tests/ResultExtensionsTests.cs
+++ b/tests/GuardCore.Tests/ResultExtensionsTests.cs
@@ -1,4 +1,4 @@
-namespace GuardCore.Tests;
+namespace Takayama.GuardCore.Tests;
 
 public class ResultExtensionsTests
 {
@@ -7,8 +7,8 @@ public void MapError_WhenResultIsFailure_ShouldTransformErrorTypeNatively()
     {
         Result<string, TestError> failureResult = TestError.ValueTooHigh;
         Result<string, AlternateError> transformed = failureResult.MapError(err =>
-            err == TestError.ValueTooHigh 
-                ? AlternateError.TranslatedFault 
+            err == TestError.ValueTooHigh
+                ? AlternateError.TranslatedFault
                 : AlternateError.None);
 
         transformed.Failed.ShouldBeTrue();
@@ -24,4 +24,4 @@ public void MapError_WhenResultIsSuccess_ShouldForwardValueUnchanged()
         transformed.IsSuccess.ShouldBeTrue();
         transformed.Value.ShouldBe("PreserveMe");
     }
-}
\ No newline at end of file
+}
diff --git a/tests/GuardCore.Tests/ResultTests.cs b/tests/GuardCore.Tests/ResultTests.cs
index 79f925f..5b30ed3 100644
--- a/tests/GuardCore.Tests/ResultTests.cs
+++ b/tests/GuardCore.Tests/ResultTests.cs
@@ -1,4 +1,4 @@
-namespace GuardCore.Tests;
+namespace Takayama.GuardCore.Tests;
 
 public enum AlternateError
 {
@@ -31,7 +31,7 @@ public void ImplicitConversion_FromValue_ShouldCreateValidSuccessResult()
         result.IsSuccess.ShouldBeTrue();
         result.Failed.ShouldBeFalse();
         result.Value.ShouldBe("SystemNormalized");
-        
+
         Should.Throw<InvalidOperationException>(() => { var _ = result.Error; })
             .Message.ShouldBe("Cannot access Error of a successful Result container.");
     }
@@ -66,15 +66,15 @@ public void Map_WhenSuccess_ShouldTransformInnerValueTypeNatively()
         mapped.IsSuccess.ShouldBeTrue();
         mapped.Value.ShouldBe(100);
     }
-    
+
     [Fact]
     public void Bind_WhenSuccess_ShouldChainMonadicOperationsWithoutAllocating()
     {
         Result<string, TestError> initial = "100";
 
-        var bound = initial.Bind(val => 
-            int.TryParse(val, out int cleanInt) 
-                ? new Result<int, TestError>(cleanInt) 
+        var bound = initial.Bind(val =>
+            int.TryParse(val, out int cleanInt)
+                ? new Result<int, TestError>(cleanInt)
                 : new Result<int, TestError>(TestError.FallbackError));
 
         bound.IsSuccess.ShouldBeTrue();
@@ -104,4 +104,4 @@ public void Deconstruct_ShouldUnpackInternalStateNatively()
         isSuccess.ShouldBeTrue();
         value.ShouldBe("DataStream");
     }
-}
\ No newline at end of file
+}
diff --git a/tests/GuardCore.Tests/TestError.cs b/tests/GuardCore.Tests/TestError.cs
index 1c8cde1..c104436 100644
--- a/tests/GuardCore.Tests/TestError.cs
+++ b/tests/GuardCore.Tests/TestError.cs
@@ -1,4 +1,4 @@
-namespace GuardCore.Tests;
+namespace Takayama.GuardCore.Tests;
 
 public enum TestError
 {
@@ -7,4 +7,4 @@ public enum TestError
     ValueTooLow,
     ValueTooHigh,
     FallbackError
-}
\ No newline at end of file
+}
diff --git a/tests/GuardCore.Tests/UniTests.cs b/tests/GuardCore.Tests/UniTests.cs
index 290383c..d7a1b0f 100644
--- a/tests/GuardCore.Tests/UniTests.cs
+++ b/tests/GuardCore.Tests/UniTests.cs
@@ -1,4 +1,4 @@
-namespace GuardCore.Tests;
+namespace Takayama.GuardCore.Tests;
 
 public class UnitTests
 {
@@ -15,4 +15,4 @@ public void UnitDefault_ShouldAlwaysBeEqualAndReturnExpectedString()
         unit1.ToString().ShouldBe("()");
         unit1.CompareTo(unit2).ShouldBe(0);
     }
-}
\ No newline at end of file
+}