diff --git a/src/riichi_hand.erl b/src/riichi_hand.erl
index 027d410..85ccce3 100644
--- a/src/riichi_hand.erl
+++ b/src/riichi_hand.erl
@@ -36,6 +36,17 @@ find(Tiles, Hand = #hand{tiles=HT, melds=HM}, Possible) ->
             find(Rest, Hand#hand{tiles=[T|HT]}, Possible)
     end.
 
+tiles(#hand{tiles=Tiles, melds=Melds}) ->
+    lists:flatten([TS || #meld{tiles=TS} <- Melds]) ++ Tiles.
+
+head(#hand{melds=Melds}) ->
+    case [M || M = #meld{type=pair} <- Melds] of
+        [Pair|_] ->
+            Pair;
+        [] ->
+            none
+    end.
+
 is_complete(#hand{tiles=[], melds=Melds}=Hand) ->
     Pairs = [M || M <- Melds, M#meld.type =:= pair],
     case length(Pairs) of
diff --git a/src/yaku.erl b/src/yaku.erl
index d3d31a2..50b6ed1 100644
--- a/src/yaku.erl
+++ b/src/yaku.erl
@@ -2,26 +2,32 @@
 
 -include("../include/riichi.hrl").
 
--compile([export_all]).
+-export([yakuhai/2,
+        tanyao/2,
+        pinfu/2,
+        chiitoitsu/2,
+        kokushi_musou/2]).
 
-
-yakuhai(#hand{melds=Melds}) ->
+yakuhai(#game{round=Round}, #player{seat=Seat, hand=#hand{melds=Melds}}) ->
     length(lists:filter(fun(#meld{type=Type, tiles=[T|_]}) ->
                                 case {Type, T} of
                                     {pair, _} ->
                                         false;
                                     {chii, _} ->
                                         false;
-                                    {_, #tile{suit=wind}} ->
-                                        % TODO: Round/Seat Winds
-                                        false;
+                                    {_, #tile{suit=wind, value=Round}} ->
+                                        true;
+                                    {_, #tile{suit=wind, value=Seat}} ->
+                                        true;
                                     {_, #tile{suit=dragon}} ->
-                                        true
+                                        true;
+                                    _ ->
+                                        false
                                 end
                         end,
                         Melds)).
 
-tanyao(#hand{melds=Melds}) ->
+tanyao(#game{}, #player{hand=Hand}) ->
     not lists:any(fun(T = #tile{}) ->
                           case T#tile.suit of
                               dragon ->
@@ -32,24 +38,30 @@ tanyao(#hand{melds=Melds}) ->
                                   lists:member(T#tile.value, [1,9])
                           end
                   end,
-                  lists:flatten([Tiles || #meld{tiles=Tiles} <- Melds])).
+                  riichi_hand:tiles(Hand)).
 
-pinfu(#hand{melds=Melds}) ->
-    % TODO: Verify closed, open wait, pair not round/seat wind
-    length([M || M = #meld{type=T} <- Melds, T =:= chii]) =:= 4.
+pinfu(#game{round=Round}, #player{seat=Seat, hand=Hand=#hand{melds=Melds}}) ->
+    % TODO: Verify closed, open wait, and pair not round/seat wind
+    Closed = lists:all(fun(T) -> T#tile.from =:= draw end, riichi_hand:tiles(Hand)),
+    Chiis = length([M || M = #meld{type=chii} <- Melds]) =:= 4,
+    #meld{type=pair, tiles=[HeadTile,HeadTile]} = riichi_hand:head(Hand),
+    NonValuePair = HeadTile#tile.value =/= Round
+        andalso HeadTile#tile.value =/= Seat
+        andalso HeadTile#tile.suit =/= dragon,
+    Closed and Chiis and NonValuePair.
 
 % 7 Pairs
-chiitoitsu(#hand{tiles=[], melds=Melds})
+chiitoitsu(#game{}, #player{hand=#hand{tiles=[], melds=Melds}})
   when length(Melds) =:= 7 ->
     Pairs = [S || S <- Melds, S#meld.type =:= pair],
     length(Pairs) =:= 7 andalso sets:size(sets:from_list(Pairs)) =:= 7.
 
 % 13 Orphans
-kokushi_musou(#hand{tiles=Tiles, melds=[#meld{type=pair, tiles=[T,T]}]}) ->
+kokushi_musou(#game{}, #player{hand=#hand{tiles=Tiles, melds=[#meld{type=pair, tiles=[T,T]}]}}) ->
     not lists:any(fun(#tile{value=V}) ->
                           lists:member(V, lists:seq(2,8))
                   end,
                   [T|Tiles])
         andalso sets:size(sets:from_list([T|Tiles])) =:= 13;
-kokushi_musou(#hand{}) ->
+kokushi_musou(#game{}, #player{}) ->
     false.
diff --git a/test/riichi_hand_tests.erl b/test/riichi_hand_tests.erl
deleted file mode 100644
index ad6816a..0000000
--- a/test/riichi_hand_tests.erl
+++ /dev/null
@@ -1,11 +0,0 @@
--module(riichi_hand_tests).
-
--include("riichi.hrl").
--include_lib("eunit/include/eunit.hrl").
-
-find_hands_test() ->
-    Tiles = [#tile{value=N, suit=pin} || N <- [1,2,3], _ <- [1,2]],
-    SetHand = #hand{sets=[#set{count=2, tile=#tile{value=N, suit=pin}, open=false} || N <- [3,2,1]]},
-    SeqHand = #hand{sets=[#seq{tiles=[#tile{value=N, suit=pin} || N <- [1,2,3]], open=false} || _ <- [1,2]]},
-    Found = [H || H <- riichi_hand:find(Tiles), H#hand.tiles =:= []],
-    ?assertEqual([SetHand, SeqHand], Found).
diff --git a/test/riichi_yaku_tests.erl b/test/riichi_yaku_tests.erl
new file mode 100644
index 0000000..fdcc788
--- /dev/null
+++ b/test/riichi_yaku_tests.erl
@@ -0,0 +1,46 @@
+-module(riichi_yaku_tests).
+
+-compile(export_all).
+
+-include("../include/riichi.hrl").
+-include_lib("eunit/include/eunit.hrl").
+
+yakuhai_test_() ->
+    Yakuhai = [lists:duplicate(3, #tile{suit=wind, value=east}),
+               lists:duplicate(3, #tile{suit=wind, value=south})
+              ] ++ [lists:duplicate(3, #tile{suit=dragon, value=V}) || V <- [red,white,green]],
+    Tiles = [#tile{suit=pin, value=V} || V <- [1,2] ++ lists:seq(1,9)],
+    Hands = [#hand{tiles=Tiles, melds=[#meld{type=pon, tiles=Y}]} || Y <- Yakuhai],
+    Players = [#player{seat=south, hand=H} || H <- Hands],
+    Games = [#game{round=east, players=[P]} || P <- Players],
+    [?_assertEqual(1, yaku:yakuhai(G, P)) || G = #game{players=[P]} <- Games].
+
+multiple_yakuhai_test() ->
+    Yakuhai = [#meld{type=pon, tiles=lists:duplicate(3, #tile{suit=dragon, value=D})} || D <- [red,green,white]],
+    Player = #player{seat=south, hand=#hand{melds=Yakuhai}},
+    ?assertEqual(3, yaku:yakuhai(#game{}, Player)).
+
+tanyao_test() ->
+    Hand = #hand{melds=[#meld{type=pon, tiles=lists:duplicate(3, #tile{suit=pin, value=2})},
+                        #meld{type=pair, tiles=lists:duplicate(2, #tile{suit=sou, value=8})},
+                        #meld{type=chii, tiles=[#tile{suit=sou, value=V} || V <- [4,5,6]]},
+                        #meld{type=chii, tiles=[#tile{suit=sou, value=V} || V <- [4,5,6]]},
+                        #meld{type=chii, tiles=[#tile{suit=man, value=V} || V <- [6,7,8]]}]},
+    ?assertEqual(true, yaku:tanyao(#game{}, #player{hand=Hand})).
+
+pinfu_test() ->
+    Hand = #hand{melds=[#meld{type=pair, tiles=lists:duplicate(2, #tile{suit=sou, value=8})},
+                        #meld{type=chii, tiles=[#tile{suit=pin, value=V} || V <- [1,2,3]]},
+                        #meld{type=chii, tiles=[#tile{suit=sou, value=V} || V <- [4,5,6]]},
+                        #meld{type=chii, tiles=[#tile{suit=sou, value=V} || V <- [4,5,6]]},
+                        #meld{type=chii, tiles=[#tile{suit=man, value=V} || V <- [6,7,8]]}]},
+    ?assertEqual(true, yaku:pinfu(#game{}, #player{hand=Hand})).
+
+chiitoitsu_test() ->
+    Hand = #hand{melds=[#meld{type=pair, tiles=lists:duplicate(2, #tile{suit=pin, value=V})} || V <- lists:seq(1,7)]},
+    ?assertEqual(true, yaku:chiitoitsu(#game{}, #player{hand=Hand})).
+
+kokushi_musou_test() ->
+    Hand = #hand{tiles=?TERMINALS ++ ?HONOURS -- [#tile{suit=pin, value=1}],
+                melds=[#meld{type=pair, tiles=lists:duplicate(2, #tile{suit=pin, value=1})}]},
+    ?assertEqual(true, yaku:kokushi_musou(#game{}, #player{hand=Hand})).