diff --git a/include/onogawa/compass.hpp b/include/onogawa/compass.hpp
new file mode 100644
index 0000000..c620415
--- /dev/null
+++ b/include/onogawa/compass.hpp
@@ -0,0 +1,22 @@
+#pragma once
+
+namespace onogawa {
+
+template <typename T> struct Compass {
+  T x;
+  T y;
+
+  constexpr Compass(T x, T y) : x(x), y(y) {}
+
+  constexpr static Compass ex() { return Compass(1.0, 0.0); }
+  constexpr static Compass ey() { return Compass(0.0, 1.0); }
+};
+
+template <typename T>
+constexpr Compass<T> operator*(const Compass<T> &a, const Compass<T> &b) {
+  return Compass(a.x * b.x - a.y * b.y, a.x * b.y + a.y * b.x);
+}
+
+using Compassd = Compass<double>;
+
+} // namespace onogawa
diff --git a/include/onogawa/onogawa.hpp b/include/onogawa/onogawa.hpp
index 0ffd9b0..3bfa161 100644
--- a/include/onogawa/onogawa.hpp
+++ b/include/onogawa/onogawa.hpp
@@ -1,145 +1,11 @@
 #pragma once
 
-namespace onogawa {
-
-template <typename T> struct Compass {
-  T x;
-  T y;
-
-  constexpr Compass(T x, T y) : x(x), y(y) {}
-
-  constexpr static Compass ex() { return Compass(1.0, 0.0); }
-  constexpr static Compass ey() { return Compass(0.0, 1.0); }
-};
-
-template <typename T>
-constexpr Compass<T> operator*(const Compass<T> &a, const Compass<T> &b) {
-  return Compass(a.x * b.x - a.y * b.y, a.x * b.y + a.y * b.x);
-}
-
-template <typename T> struct Point2 {
-  T x;
-  T y;
-
-  constexpr Point2(T x, T y) : x(x), y(y) {}
-
-  constexpr static Point2 ex() { return Point2(1.0, 0.0); }
-  constexpr static Point2 ey() { return Point2(0.0, 1.0); }
-};
-
-template <typename T>
-constexpr Point2<T> operator+(const Point2<T> &a, const Point2<T> &b) {
-  return Point2(a.x + b.x, a.y + b.y);
-}
-
-template <typename T>
-constexpr Point2<T> operator*(const Compass<T> &compass,
-                              const Point2<T> &point) {
-  return Point2(compass.x * point.x - compass.y * point.y,
-                compass.x * point.y - compass.y * point.x);
-}
-
-template <typename T> struct Pose2 {
-  Compass<T> orientation;
-  Point2<T> position;
-
-  constexpr Pose2(const Compass<T> &orientation, const Point2<T> &position)
-      : orientation(orientation), position(position) {}
-};
-
-template <typename T>
-constexpr Pose2<T> operator*(const Pose2<T> &a, const Pose2<T> &b) {
-  return Pose2(a.orientation * b.orientation,
-               a.orientation * b.position + a.position);
-}
-
-template <typename T> struct Quaternion {
-  T w;
-  T x;
-  T y;
-  T z;
-
-  constexpr Quaternion(T w, T x, T y, T z) : w(w), x(x), y(y), z(z) {}
-
-  constexpr static Quaternion ew() { return Quaternion(1.0, 0.0, 0.0, 0.0); };
-  constexpr static Quaternion ex() { return Quaternion(0.0, 1.0, 0.0, 0.0); };
-  constexpr static Quaternion ey() { return Quaternion(0.0, 0.0, 1.0, 0.0); };
-  constexpr static Quaternion ez() { return Quaternion(0.0, 0.0, 0.0, 1.0); };
-};
-
-template <typename T>
-constexpr Quaternion<T> operator*(const Quaternion<T> &a,
-                                  const Quaternion<T> &b) {
-  return Quaternion(a.w * b.w - a.x * b.x - a.y * b.y - a.z * b.z,
-                    a.w * b.x + a.x * b.w + a.y * b.z - a.z * b.y,
-                    a.w * b.y - a.x * b.z + a.y * b.w + a.z * b.x,
-                    a.w * b.z + a.x * b.y - a.y * b.x + a.z * b.w);
-}
-
-template <typename T> struct Point3 {
-  T x;
-  T y;
-  T z;
-
-  constexpr Point3(T x, T y, T z) : x(x), y(y), z(z) {}
-
-  constexpr static Point3 ex() { return Point3(1.0, 0.0, 0.0); }
-  constexpr static Point3 ey() { return Point3(0.0, 1.0, 0.0); }
-  constexpr static Point3 ez() { return Point3(0.0, 0.0, 1.0); }
-};
-
-template <typename T>
-constexpr Point3<T> operator+(const Point3<T> &a, const Point3<T> &b) {
-  return Point3(a.x + b.x, a.y + b.y, a.z + b.z);
-}
-
-template <typename T>
-constexpr Point3<T> operator*(const Quaternion<T> &q, const Point3<T> &point) {
-  const T s = 2.0 / (q.w * q.w + q.x * q.x + q.y * q.y + q.z * q.z);
-
-  const T xs = q.x * s;
-  const T ys = q.y * s;
-  const T zs = q.z * s;
-
-  const T wxs = q.w * xs;
-  const T wys = q.w * ys;
-  const T wzs = q.w * zs;
-
-  const T xxs = q.x * xs;
-  const T xys = q.x * ys;
-  const T xzs = q.x * zs;
-
-  const T yys = q.y * ys;
-  const T yzs = q.y * zs;
-
-  const T zzs = q.z * zs;
-
-  return Point3(
-      (1 - yys - zzs) * point.x + (xys - wzs) * point.y + (xzs + wys) * point.z,
-      (xys + wzs) * point.x + (1 - xxs - zzs) * point.y + (yzs - wxs) * point.z,
-      (xzs - wys) * point.x + (yzs + wxs) * point.y +
-          (1 - xxs - yys) * point.z);
-}
-
-template <typename T> struct Pose3 {
-  Quaternion<T> orientation;
-  Point3<T> position;
-
-  constexpr Pose3(const Quaternion<T> &orientation, const Point3<T> &position)
-      : orientation(orientation), position(position) {}
-};
-
-template <typename T>
-constexpr Pose3<T> operator*(const Pose3<T> &a, const Pose3<T> &b) {
-  return Pose3(a.orientation * b.orientation,
-               a.orientation * b.position + a.position);
-}
-
-using Compassd = Compass<double>;
-using Point2d = Point2<double>;
-using Pose2d = Pose2<double>;
-using Quaterniond = Quaternion<double>;
-using Point3d = Point3<double>;
-using Pose3d = Pose3<double>;
-
-} // namespace onogawa
+// 2-D
+#include "onogawa/compass.hpp"
+#include "onogawa/point2.hpp"
+#include "onogawa/pose2.hpp"
+
+// 3-D
+#include "onogawa/point3.hpp"
+#include "onogawa/pose3.hpp"
+#include "onogawa/quaternion.hpp"
diff --git a/include/onogawa/point2.hpp b/include/onogawa/point2.hpp
new file mode 100644
index 0000000..5510d28
--- /dev/null
+++ b/include/onogawa/point2.hpp
@@ -0,0 +1,31 @@
+#pragma once
+
+#include "onogawa/compass.hpp"
+
+namespace onogawa {
+
+template <typename T> struct Point2 {
+  T x;
+  T y;
+
+  constexpr Point2(T x, T y) : x(x), y(y) {}
+
+  constexpr static Point2 ex() { return Point2(1.0, 0.0); }
+  constexpr static Point2 ey() { return Point2(0.0, 1.0); }
+};
+
+template <typename T>
+constexpr Point2<T> operator+(const Point2<T> &a, const Point2<T> &b) {
+  return Point2(a.x + b.x, a.y + b.y);
+}
+
+template <typename T>
+constexpr Point2<T> operator*(const Compass<T> &compass,
+                              const Point2<T> &point) {
+  return Point2(compass.x * point.x - compass.y * point.y,
+                compass.x * point.y - compass.y * point.x);
+}
+
+using Point2d = Point2<double>;
+
+} // namespace onogawa
\ No newline at end of file
diff --git a/include/onogawa/point3.hpp b/include/onogawa/point3.hpp
new file mode 100644
index 0000000..a076013
--- /dev/null
+++ b/include/onogawa/point3.hpp
@@ -0,0 +1,54 @@
+#pragma once
+
+#include "onogawa/quaternion.hpp"
+
+namespace onogawa {
+
+template <typename T> struct Point3 {
+  T x;
+  T y;
+  T z;
+
+  constexpr Point3(T x, T y, T z) : x(x), y(y), z(z) {}
+
+  constexpr static Point3 ex() { return Point3(1.0, 0.0, 0.0); }
+  constexpr static Point3 ey() { return Point3(0.0, 1.0, 0.0); }
+  constexpr static Point3 ez() { return Point3(0.0, 0.0, 1.0); }
+};
+
+template <typename T>
+constexpr Point3<T> operator+(const Point3<T> &a, const Point3<T> &b) {
+  return Point3(a.x + b.x, a.y + b.y, a.z + b.z);
+}
+
+template <typename T>
+constexpr Point3<T> operator*(const Quaternion<T> &q, const Point3<T> &point) {
+  const T s = 2.0 / (q.w * q.w + q.x * q.x + q.y * q.y + q.z * q.z);
+
+  const T xs = q.x * s;
+  const T ys = q.y * s;
+  const T zs = q.z * s;
+
+  const T wxs = q.w * xs;
+  const T wys = q.w * ys;
+  const T wzs = q.w * zs;
+
+  const T xxs = q.x * xs;
+  const T xys = q.x * ys;
+  const T xzs = q.x * zs;
+
+  const T yys = q.y * ys;
+  const T yzs = q.y * zs;
+
+  const T zzs = q.z * zs;
+
+  return Point3(
+      (1 - yys - zzs) * point.x + (xys - wzs) * point.y + (xzs + wys) * point.z,
+      (xys + wzs) * point.x + (1 - xxs - zzs) * point.y + (yzs - wxs) * point.z,
+      (xzs - wys) * point.x + (yzs + wxs) * point.y +
+          (1 - xxs - yys) * point.z);
+}
+
+using Point3d = Point3<double>;
+
+} // namespace onogawa
diff --git a/include/onogawa/pose2.hpp b/include/onogawa/pose2.hpp
new file mode 100644
index 0000000..f8667e3
--- /dev/null
+++ b/include/onogawa/pose2.hpp
@@ -0,0 +1,24 @@
+#pragma once
+
+#include "onogawa/compass.hpp"
+#include "onogawa/point2.hpp"
+
+namespace onogawa {
+
+template <typename T> struct Pose2 {
+  Compass<T> orientation;
+  Point2<T> position;
+
+  constexpr Pose2(const Compass<T> &orientation, const Point2<T> &position)
+      : orientation(orientation), position(position) {}
+};
+
+template <typename T>
+constexpr Pose2<T> operator*(const Pose2<T> &a, const Pose2<T> &b) {
+  return Pose2(a.orientation * b.orientation,
+               a.orientation * b.position + a.position);
+}
+
+using Pose2d = Pose2<double>;
+
+} // namespace onogawa
diff --git a/include/onogawa/pose3.hpp b/include/onogawa/pose3.hpp
new file mode 100644
index 0000000..087957b
--- /dev/null
+++ b/include/onogawa/pose3.hpp
@@ -0,0 +1,24 @@
+#pragma once
+
+#include "onogawa/point3.hpp"
+#include "onogawa/quaternion.hpp"
+
+namespace onogawa {
+
+template <typename T> struct Pose3 {
+  Quaternion<T> orientation;
+  Point3<T> position;
+
+  constexpr Pose3(const Quaternion<T> &orientation, const Point3<T> &position)
+      : orientation(orientation), position(position) {}
+};
+
+template <typename T>
+constexpr Pose3<T> operator*(const Pose3<T> &a, const Pose3<T> &b) {
+  return Pose3(a.orientation * b.orientation,
+               a.orientation * b.position + a.position);
+}
+
+using Pose3d = Pose3<double>;
+
+} // namespace onogawa
\ No newline at end of file
diff --git a/include/onogawa/quaternion.hpp b/include/onogawa/quaternion.hpp
new file mode 100644
index 0000000..4984d5e
--- /dev/null
+++ b/include/onogawa/quaternion.hpp
@@ -0,0 +1,30 @@
+#pragma once
+
+namespace onogawa {
+
+template <typename T> struct Quaternion {
+  T w;
+  T x;
+  T y;
+  T z;
+
+  constexpr Quaternion(T w, T x, T y, T z) : w(w), x(x), y(y), z(z) {}
+
+  constexpr static Quaternion ew() { return Quaternion(1.0, 0.0, 0.0, 0.0); };
+  constexpr static Quaternion ex() { return Quaternion(0.0, 1.0, 0.0, 0.0); };
+  constexpr static Quaternion ey() { return Quaternion(0.0, 0.0, 1.0, 0.0); };
+  constexpr static Quaternion ez() { return Quaternion(0.0, 0.0, 0.0, 1.0); };
+};
+
+template <typename T>
+constexpr Quaternion<T> operator*(const Quaternion<T> &a,
+                                  const Quaternion<T> &b) {
+  return Quaternion(a.w * b.w - a.x * b.x - a.y * b.y - a.z * b.z,
+                    a.w * b.x + a.x * b.w + a.y * b.z - a.z * b.y,
+                    a.w * b.y - a.x * b.z + a.y * b.w + a.z * b.x,
+                    a.w * b.z + a.x * b.y - a.y * b.x + a.z * b.w);
+}
+
+using Quaterniond = Quaternion<double>;
+
+} // namespace onogawa
\ No newline at end of file