diff --git a/lib/bokken/guards.ex b/lib/bokken/guards.ex
index 189eff5f..57477e27 100644
--- a/lib/bokken/guards.ex
+++ b/lib/bokken/guards.ex
@@ -18,6 +18,20 @@ defmodule Bokken.Guards do
   defguard is_guardian(conn) when conn.assigns.current_user.role === :guardian
   defguard is_registered(conn) when conn.assigns.current_user.registered
 
+  @doc """
+  Defines the way to proceed in specific roles situations.
+
+  ## Examples
+
+      defguard is_ninja_guardian(user, ninja) when user.role == :guardian and user.guardian.id == ninja.guardian.id
+      Means to return True when a user is the ninja's guardian.
+
+  """
+  defguard is_ninja_guardian(user, ninja)
+           when user.role == :guardian and user.guardian.id == ninja.guardian.id
+
+  defguard is_ninja_user(user, ninja) when user.role == :ninja and user.id == ninja.user_id
+
   @doc """
   Defines the way to proceed in specific error situations.
 
diff --git a/lib/bokken_web/controllers/ninja/ninja_controller.ex b/lib/bokken_web/controllers/ninja/ninja_controller.ex
index e6e3bd78..be7cd3c9 100644
--- a/lib/bokken_web/controllers/ninja/ninja_controller.ex
+++ b/lib/bokken_web/controllers/ninja/ninja_controller.ex
@@ -14,20 +14,25 @@ defmodule BokkenWeb.NinjaController do
       when is_map_key(params, "badge_id")
       when is_map_key(params, "event_id") do
     ninjas = Accounts.list_ninjas()
-    render(conn, :index, ninjas: ninjas)
+    render(conn, :index, %{ninjas: ninjas, current_user: conn.assigns.current_user})
   end
 
-  def index(conn, _params) when is_guardian(conn) or is_organizer(conn) do
-    guardian_id = conn.assigns.current_user.guardian.id
+  def index(conn, _params) when is_guardian(conn) do
+    current_user = Accounts.get_user!(conn.assigns.current_user.id, [:guardian])
+    guardian_id = current_user.guardian.id
     guardian = Accounts.get_guardian!(guardian_id, [:ninjas])
-    render(conn, :index, ninjas: guardian.ninjas)
+
+    render(conn, :index, %{
+      ninjas: guardian.ninjas,
+      current_user: current_user
+    })
   end
 
   def create(conn, %{"event_id" => event_id, "ninja_id" => ninja_id})
       when is_guardian(conn) or is_organizer(conn) do
     with {:ok, %Event{} = event, %Lecture{} = _lecture} <-
            Accounts.register_ninja_in_event(event_id, ninja_id) do
-      render(conn, :index, ninjas: event.ninjas)
+      render(conn, :index, %{ninjas: event.ninjas, current_user: conn.assigns.current_user})
     end
   end
 
@@ -39,7 +44,7 @@ defmodule BokkenWeb.NinjaController do
       conn
       |> put_status(:created)
       |> put_resp_header("location", ~p"/api/teams/#{ninja}")
-      |> render(:show, ninja: ninja)
+      |> render(:show, %{ninja: ninja, current_user: conn.assigns.current_user})
     end
   end
 
@@ -52,18 +57,18 @@ defmodule BokkenWeb.NinjaController do
       conn
       |> put_status(:created)
       |> put_resp_header("location", ~p"/api/ninjas/#{ninja}")
-      |> render(:show, ninja: ninja)
+      |> render(:show, %{ninja: ninja, current_user: conn.assigns.current_user})
     end
   end
 
   def show(conn, %{"id" => id}) do
-    ninja = Accounts.get_ninja!(id, [:skills])
-    render(conn, :show, ninja: ninja)
+    ninja = Accounts.get_ninja!(id, [:skills, :guardian])
+    render(conn, :show, %{ninja: ninja, current_user: conn.assigns.current_user})
   end
 
   def show(conn, %{"discord_id" => discord_id}) do
     with {:ok, %Ninja{} = ninja} <- Accounts.get_ninja_by_discord(discord_id) do
-      render(conn, :show, ninja: ninja)
+      render(conn, :show, %{ninja: ninja, current_user: conn.assigns.current_user})
     end
   end
 
@@ -72,14 +77,14 @@ defmodule BokkenWeb.NinjaController do
     ninja = Accounts.get_ninja!(id)
 
     with {:ok, %Ninja{} = ninja} <- Accounts.update_ninja(ninja, ninja_params) do
-      render(conn, :show, ninja: ninja)
+      render(conn, :show, %{ninja: ninja, current_user: conn.assigns.current_user})
     end
   end
 
   def update(conn, %{"discord_id" => discord_id, "ninja" => ninja_params}) do
     with {:ok, %Ninja{} = ninja} <- Accounts.get_ninja_by_discord(discord_id),
          {:ok, %Ninja{} = ninja} <- Accounts.update_ninja(ninja, ninja_params) do
-      render(conn, :show, ninja: ninja)
+      render(conn, :show, %{ninja: ninja, current_user: conn.assigns.current_user})
     end
   end
 
diff --git a/lib/bokken_web/controllers/ninja/ninja_json.ex b/lib/bokken_web/controllers/ninja/ninja_json.ex
index 80dcb9b4..f1eaea38 100644
--- a/lib/bokken_web/controllers/ninja/ninja_json.ex
+++ b/lib/bokken_web/controllers/ninja/ninja_json.ex
@@ -2,21 +2,17 @@ defmodule BokkenWeb.NinjaJSON do
   alias Bokken.Uploaders.Avatar
   alias BokkenWeb.SkillJSON
 
-  def index(%{ninjas: ninjas}) do
-    %{data: for(ninja <- ninjas, do: data(ninja))}
-  end
+  import Bokken.Guards, only: [is_ninja_guardian: 2, is_ninja_user: 2]
 
-  def show(%{ninja: ninja}) do
-    %{data: data(ninja)}
+  def index(%{ninjas: ninjas, current_user: current_user}) do
+    %{data: for(ninja <- ninjas, do: data(ninja, current_user))}
   end
 
-  def ninja(%{ninja: ninja, current_user: current_user}) do
-    data(ninja)
-    |> Map.merge(personal(ninja, current_user))
-    |> Map.merge(sensitive(ninja, current_user))
+  def show(%{ninja: ninja, current_user: current_user}) do
+    %{data: data(ninja, current_user)}
   end
 
-  def data(ninja) do
+  def data(ninja, current_user) do
     %{
       id: ninja.id,
       photo: Avatar.url({ninja.photo, ninja}, :thumb),
@@ -27,11 +23,15 @@ defmodule BokkenWeb.NinjaJSON do
       since: ninja.inserted_at,
       guardian_id: ninja.guardian_id
     }
+    |> Map.merge(personal(ninja, current_user))
+    |> Map.merge(sensitive(ninja, current_user))
     |> Map.merge(skills(ninja))
   end
 
   defp personal(ninja, current_user)
-       when current_user.role == :organizer or current_user.id == ninja.id do
+       when current_user.role == :organizer or
+              is_ninja_guardian(current_user, ninja) or
+              is_ninja_user(current_user, ninja) do
     %{
       birthday: ninja.birthday
     }
diff --git a/lib/bokken_web/views/auth_view.ex b/lib/bokken_web/views/auth_view.ex
index 56b7d32e..5a3ee124 100644
--- a/lib/bokken_web/views/auth_view.ex
+++ b/lib/bokken_web/views/auth_view.ex
@@ -24,7 +24,7 @@ defmodule BokkenWeb.AuthView do
   end
 
   def render("me.json", %{user: %{role: :ninja, ninja: ninja} = user}) do
-    NinjaJSON.ninja(%{ninja: ninja, current_user: user})
+    NinjaJSON.data(ninja, user)
     |> Map.merge(render_one(user, AuthView, "user.json"))
     |> Map.put(:ninja_id, ninja.id)
   end
diff --git a/lib/bokken_web/views/enrollment_view.ex b/lib/bokken_web/views/enrollment_view.ex
index 919492ed..b571ee28 100644
--- a/lib/bokken_web/views/enrollment_view.ex
+++ b/lib/bokken_web/views/enrollment_view.ex
@@ -39,7 +39,7 @@ defmodule BokkenWeb.EnrollmentView do
 
   defp ninja(enrollment, current_user) do
     if Ecto.assoc_loaded?(enrollment.ninja) do
-      %{ninja: NinjaJSON.ninja(%{ninja: enrollment.ninja, current_user: current_user})}
+      %{ninja: NinjaJSON.data(enrollment.ninja, current_user)}
     else
       %{ninja_id: enrollment.ninja_id}
     end
diff --git a/lib/bokken_web/views/lecture_view.ex b/lib/bokken_web/views/lecture_view.ex
index a2324756..82123371 100644
--- a/lib/bokken_web/views/lecture_view.ex
+++ b/lib/bokken_web/views/lecture_view.ex
@@ -35,7 +35,7 @@ defmodule BokkenWeb.LectureView do
 
   defp ninja(lecture, current_user) do
     if Ecto.assoc_loaded?(lecture.ninja) do
-      %{ninja: NinjaJSON.ninja(%{ninja: lecture.ninja, current_user: current_user})}
+      %{ninja: NinjaJSON.data(lecture.ninja, current_user)}
     else
       %{ninja_id: lecture.ninja_id}
     end
diff --git a/test/bokken_web/controllers/ninja_json_test.exs b/test/bokken_web/controllers/ninja_json_test.exs
index 2ae7e248..8afd90c8 100644
--- a/test/bokken_web/controllers/ninja_json_test.exs
+++ b/test/bokken_web/controllers/ninja_json_test.exs
@@ -5,37 +5,142 @@ defmodule Bokken.NinjaJSONTest do
   alias Bokken.Uploaders.Avatar
   alias BokkenWeb.NinjaJSON
 
-  test "data" do
-    ninja = build(:ninja)
-    rendered_ninja = NinjaJSON.data(ninja)
-
-    assert rendered_ninja == %{
-             id: ninja.id,
-             photo: Avatar.url({ninja.photo, ninja}),
-             first_name: ninja.first_name,
-             last_name: ninja.last_name,
-             belt: ninja.belt,
-             socials: ninja.socials,
-             since: ninja.inserted_at,
-             guardian_id: ninja.guardian_id
-           }
+  describe "render as guardian" do
+    setup do
+      guardian = insert(:guardian)
+      user = insert(:user, role: :guardian, guardian: guardian)
+      ninja = insert(:ninja, guardian: guardian)
+
+      {:ok, ninja: ninja, current_user: user}
+    end
+
+    test "show", %{ninja: ninja, current_user: user} do
+      rendered_ninja = NinjaJSON.show(%{ninja: ninja, current_user: user})
+
+      assert rendered_ninja ==
+               %{
+                 data: %{
+                   id: ninja.id,
+                   photo: Avatar.url({ninja.photo, ninja}),
+                   first_name: ninja.first_name,
+                   last_name: ninja.last_name,
+                   belt: ninja.belt,
+                   socials: ninja.socials,
+                   since: ninja.inserted_at,
+                   birthday: ninja.birthday,
+                   guardian_id: ninja.guardian_id
+                 }
+               }
+    end
+
+    test "index", %{ninja: ninja, current_user: user} do
+      ninjas = insert_list(5, :ninja, guardian: ninja.guardian)
+      rendered_ninjas = NinjaJSON.index(%{ninjas: ninjas, current_user: user})
+
+      assert 5 == Enum.count(rendered_ninjas[:data])
+    end
+  end
+
+  describe "render as not ninja's guardian" do
+    setup do
+      guardian = insert(:guardian)
+      user = insert(:user, role: :guardian)
+      ninja = insert(:ninja, guardian: guardian)
+
+      {:ok, ninja: ninja, current_user: user}
+    end
+
+    test "show", %{ninja: ninja, current_user: user} do
+      rendered_ninja = NinjaJSON.show(%{ninja: ninja, current_user: user})
+
+      assert rendered_ninja ==
+               %{
+                 data: %{
+                   id: ninja.id,
+                   photo: Avatar.url({ninja.photo, ninja}),
+                   first_name: ninja.first_name,
+                   last_name: ninja.last_name,
+                   belt: ninja.belt,
+                   socials: ninja.socials,
+                   since: ninja.inserted_at,
+                   guardian_id: ninja.guardian_id
+                 }
+               }
+    end
+
+    test "index", %{ninja: ninja, current_user: user} do
+      ninjas = insert_list(5, :ninja, guardian: ninja.guardian)
+      rendered_ninjas = NinjaJSON.index(%{ninjas: ninjas, current_user: user})
+
+      assert 5 == Enum.count(rendered_ninjas[:data])
+    end
   end
 
-  test "show" do
-    ninja = build(:ninja)
-    rendered_ninja = NinjaJSON.show(%{ninja: ninja})
+  describe "render as mentor" do
+    setup do
+      user = insert(:user, role: :mentor)
+      ninja = insert(:ninja)
+      {:ok, ninja: ninja, current_user: user}
+    end
+
+    test "show", %{ninja: ninja, current_user: user} do
+      rendered_ninja = NinjaJSON.show(%{ninja: ninja, current_user: user})
+
+      assert rendered_ninja ==
+               %{
+                 data: %{
+                   id: ninja.id,
+                   photo: Avatar.url({ninja.photo, ninja}),
+                   first_name: ninja.first_name,
+                   last_name: ninja.last_name,
+                   belt: ninja.belt,
+                   socials: ninja.socials,
+                   since: ninja.inserted_at,
+                   notes: nil,
+                   guardian_id: ninja.guardian_id
+                 }
+               }
+    end
 
-    assert rendered_ninja == %{
-             data: NinjaJSON.data(ninja)
-           }
+    test "index", %{ninja: ninja, current_user: user} do
+      ninjas = insert_list(5, :ninja, guardian: ninja.guardian)
+      rendered_ninjas = NinjaJSON.index(%{ninjas: ninjas, current_user: user})
+
+      assert 5 == Enum.count(rendered_ninjas[:data])
+    end
   end
 
-  test "index" do
-    ninjas = build_list(5, :ninja)
-    rendered_ninjas = NinjaJSON.index(%{ninjas: ninjas})
+  describe "render as ninja" do
+    setup do
+      user = insert(:user, role: :ninja)
+      ninja = insert(:ninja, user: user)
+      {:ok, ninja: ninja, current_user: user}
+    end
+
+    test "show", %{ninja: ninja, current_user: user} do
+      rendered_ninja = NinjaJSON.show(%{ninja: ninja, current_user: user})
+
+      assert rendered_ninja ==
+               %{
+                 data: %{
+                   id: ninja.id,
+                   photo: Avatar.url({ninja.photo, ninja}),
+                   first_name: ninja.first_name,
+                   last_name: ninja.last_name,
+                   belt: ninja.belt,
+                   socials: ninja.socials,
+                   since: ninja.inserted_at,
+                   birthday: ninja.birthday,
+                   guardian_id: ninja.guardian_id
+                 }
+               }
+    end
+
+    test "index", %{ninja: ninja, current_user: user} do
+      ninjas = insert_list(5, :ninja, guardian: ninja.guardian)
+      rendered_ninjas = NinjaJSON.index(%{ninjas: ninjas, current_user: user})
 
-    assert rendered_ninjas == %{
-             data: Enum.map(ninjas, &NinjaJSON.data(&1))
-           }
+      assert 5 == Enum.count(rendered_ninjas[:data])
+    end
   end
 end