diff --git a/Makefile b/Makefile
index f2a9371..a411c8b 100644
--- a/Makefile
+++ b/Makefile
@@ -69,6 +69,11 @@ all: | clean
 .PHONY: install
 .PHONY: uninstall
 
+.PHONY: test
+test:
+	@rm -f $(PROJECT)-cpp-test
+	@$(MAKE) $(PROJECT)-cpp-test
+
 # Targets
 
 dirs:
@@ -130,3 +135,7 @@ uninstall:
 	-rm $(DESTDIR)$(PREFIX)/lib/lib$(PROJECT).{a,so}
 	cd $(INCLUDE) && find . -type f | xargs -I {} rm "$(DESTDIR)$(PREFIX)/include/{}"
 	-rmdir $(DESTDIR)$(PREFIX)/include/$(PROJECT)
+
+$(PROJECT)-cpp-test: lib$(PROJECT).a
+	g++ -O3 --std=gnu++20 -Iinclude/ -g -Wall -Wextra src/test/*.cpp -o $@ -l:$<
+	valgrind ./$@
diff --git a/include/cow/area.hpp b/include/cow/area.hpp
new file mode 100644
index 0000000..8c204ef
--- /dev/null
+++ b/include/cow/area.hpp
@@ -0,0 +1,28 @@
+// `Area` is a copyable type that opaquely represents either `Cow` or `Cow::Fake`.
+#pragma once
+
+#include <memory>
+#include <utility>
+
+#include <cow.hpp>
+
+struct Area {
+	Area(size_t sz);
+	Area(const Area& area);
+	Area(Area&& area);
+
+	inline const Cow* operator->() const { return _area.get(); }
+	inline Cow* operator->() { return _area.get(); }
+
+	inline const Cow* operator*() const { return _area.get(); }
+	inline Cow* operator*() { return _area.get(); }
+
+	inline operator const Cow&() const { return *_area.get(); }
+	inline operator Cow&() { return *_area.get(); }
+
+	inline bool is_clone() const { return dynamic_cast<Cow::Fake*>(_area.get()) != nullptr; }
+
+	~Area();
+	private:
+	const std::unique_ptr<Cow> _area;
+};
diff --git a/src/area.cpp b/src/area.cpp
new file mode 100644
index 0000000..af42b58
--- /dev/null
+++ b/src/area.cpp
@@ -0,0 +1,8 @@
+#include <cow/area.hpp>
+
+Area::Area(size_t sz) : _area(std::make_unique<Cow>(sz)){}
+Area::Area(const Area& copy) : 
+	_area(std::make_unique<Cow::Fake>(*copy._area.get())){}
+Area::Area(Area&& move) :
+	_area(std::move(*const_cast<std::unique_ptr<Cow>*>(&move._area))){}
+Area::~Area(){}
diff --git a/src/test/main.cpp b/src/test/main.cpp
index 5c8cada..25c3d44 100644
--- a/src/test/main.cpp
+++ b/src/test/main.cpp
@@ -7,6 +7,8 @@
 
 #include <vector>
 
+#include <cow/area.hpp>
+
 using namespace _cow_util;
 
 /// UTF8 multibyte 4.
@@ -35,7 +37,7 @@ struct utf8_t {
 	}
 
 	constexpr inline utf8_t(const char* c) {
-		for(int i=0;i<MULTIBYTE && (data[i] = c[i]); i++) (void)0;	
+		for(size_t i=0;i<MULTIBYTE && (data[i] = c[i]); i++) (void)0;	
 	}
 
 	constexpr inline utf8_t(const Unicode& data) : data(data) {}
@@ -53,6 +55,7 @@ struct utf8_t {
 	Unicode data;
 };
 
+
 namespace Tiling {
 	struct Map;
 
@@ -138,6 +141,8 @@ namespace Tiling {
 	};
 }
 
+
+
 template<typename T = unsigned char>
 void print_slice(Slice<T> memory)
 {
@@ -165,11 +170,23 @@ void moving_cow(Cow moved)
 
 int main()
 {
+	Area area(4000);
+	write_fake(area, "Hello???");
+	Area area2 = area;
+	write_fake(area2, "Hi");
+	Area area3 = std::move(area2);
+	Area area4 = std::move(area);
+	read_fake(area3);
+	read_fake(area4);
+
+	printf("Is clone: a1: %d, a2: %d\n", area4.is_clone(), area3.is_clone());
+
 	utf8_t ch = "あ";
 	utf8_t ch2('a');
 	utf8_t ch3 = ch.c_str();
 	utf8_t ch4 = ch3.data;
 	utf8_t ch5 = ch4;
+	(void)ch5;
 	printf("Test: %s, %s, %s\n", (const char*)ch, ch2.c_str(), ch3.c_str());
 
 	Cow real(4096);