diff --git a/data/data_symbols.csv b/data/data_symbols.csv
index 4b59a366..ea36792b 100644
--- a/data/data_symbols.csv
+++ b/data/data_symbols.csv
@@ -17,6 +17,8 @@
 0x00000071024C1600,_ZTVN3agl3utl9ParameterIN4sead15FixedSafeStringILi64EEEEE
 0x00000071024C16A0,_ZTVN3agl3utl9ParameterIN4sead15FixedSafeStringILi256EEEEE
 0x00000071024C1740,_ZTVN3agl3utl9ParameterIN4sead14SafeStringBaseIcEEEE
+0x00000071024D8D58,_ZTVN4ksys3act2ai10ActionBaseE
+0x0000007102513268,_ZTVN4ksys3act2ai2AiE
 0x00000071025F75B0,pfnc_nvnDeviceBuilderSetDefaults
 0x00000071025F75B8,pfnc_nvnDeviceBuilderSetFlags
 0x00000071025F75C0,pfnc_nvnDeviceInitialize
diff --git a/data/uking_functions.csv b/data/uking_functions.csv
index 69892914..5229288c 100644
--- a/data/uking_functions.csv
+++ b/data/uking_functions.csv
@@ -1322,13 +1322,13 @@
 0x000000710004c1d8,AI_AIOrActionBase::ret1_0,8,_ZN4ksys3act2ai10ActionBase3m18Ev
 0x000000710004c1e0,AI_AIOrActionBase::m19_null,4,_ZN4ksys3act2ai10ActionBase3m19Ev
 0x000000710004c1e4,AI_AIOrActionBase::ret0_0,8,_ZN4ksys3act2ai10ActionBase3m22Ev
-0x000000710004c1ec,AI_AIOrActionBase::ret0_1,8,_ZN4ksys3act2ai10ActionBase3m24Ev
+0x000000710004c1ec,AI_AIOrActionBase::ret0_1,8,_ZNK4ksys3act2ai10ActionBase14getNumChildrenEv
 0x000000710004c1f4,AI_AIOrActionBase::ret1_1,8,_ZN4ksys3act2ai10ActionBase3m25Ev
 0x000000710004c1fc,AI_AIOrActionBase::ret0_5,8,_ZNK4ksys3act2ai10ActionBase15getCurrentChildEv
 0x000000710004c204,AI_ActionBase::isAction,8,_ZNK4ksys3act2ai6Action8isActionEv
 0x000000710004c20c,AI_AIOrActionBase::m28,16,_ZN4ksys3act2ai10ActionBase7reenterEPS2_
 0x000000710004c21c,AI_AIOrActionBase::m29_null,4,_ZN4ksys3act2ai10ActionBase9postLeaveEv
-0x000000710004c220,AI_AIOrActionBase::ret0_6,8,_ZNK4ksys3act2ai10ActionBase9getActionEi
+0x000000710004c220,AI_AIOrActionBase::ret0_6,8,_ZNK4ksys3act2ai10ActionBase8getChildEi
 0x000000710004c228,sub_710004C228,140,
 0x000000710004c2b4,sub_710004C2B4,140,
 0x000000710004c340,AI_Action_AnimeDrivenTurn::ctor,104,
@@ -20064,11 +20064,11 @@
 0x00000071002f6548,AI_AI_ActorWaterDepthSelect::m4,36,
 0x00000071002f656c,AI_AI_ActorWaterDepthSelect::m5,36,
 0x00000071002f6590,AI_AI_ActorWaterDepthSelect::m6,36,
-0x00000071002f65b4,AI_AIBase::m24,8,
-0x00000071002f65bc,AI_AIBase::isAction,8,
-0x00000071002f65c4,AI_AIBase::m29,8,
-0x00000071002f65cc,AI_AIBase::m30,28,
-0x00000071002f65e8,AI_AIBase::handlePendingChildChange,12,
+0x00000071002f65b4,AI_AIBase::m24,8,_ZNK4ksys3act2ai2Ai14getNumChildrenEv
+0x00000071002f65bc,AI_AIBase::isAction,8,_ZNK4ksys3act2ai2Ai8isActionEv
+0x00000071002f65c4,AI_AIBase::m29,8,_ZN4ksys3act2ai2Ai9postLeaveEv?
+0x00000071002f65cc,AI_AIBase::m30,28,_ZNK4ksys3act2ai2Ai8getChildEi
+0x00000071002f65e8,AI_AIBase::handlePendingChildChange,12,_ZN4ksys3act2ai2Ai25handlePendingChildChange_Ev
 0x00000071002f65f4,AI_AI_AddBasicLinkOn::ctor,104,
 0x00000071002f665c,AI_AI_AddBasicLinkOn::dtor,88,
 0x00000071002f66b4,sub_71002F66B4,64,
@@ -22848,7 +22848,7 @@
 0x0000007100367694,AI_AI_DragonDropItemTargetRootAI::dtorDelete,36,
 0x00000071003676b8,AI_AI_DragonDropItemTargetRootAI::rtti1,288,
 0x00000071003677d8,AI_AI_DragonDropItemTargetRootAI::rtti2,92,
-0x0000007100367834,AI_AIBase::calc,4,
+0x0000007100367834,AI_AIBase::calc,4,_ZN4ksys3act2ai2Ai5calc_Ev
 0x0000007100367838,AI_AI_DragonElecRoot::ctor,48,
 0x0000007100367868,j_AI_AIDragonRoot::dtor,4,
 0x000000710036786c,AI_AI_DragonElecRoot::dtorDelete,36,
@@ -92253,13 +92253,13 @@
 0x00000071011dde80,sub_71011DDE80,8,
 0x00000071011dde88,sub_71011DDE88,48,
 0x00000071011ddeb8,sub_71011DDEB8,92,
-0x00000071011ddf14,AI_AIBase::ctor,64,
-0x00000071011ddf54,AI_AIBase::dtor,84,
-0x00000071011ddfa8,AI_AIBase::dtorDelete,92,
+0x00000071011ddf14,AI_AIBase::ctor,64,_ZN4ksys3act2ai2AiC1ERKNS1_10ActionBase7InitArgE
+0x00000071011ddf54,AI_AIBase::dtor,84,_ZN4ksys3act2ai2AiD1Ev
+0x00000071011ddfa8,AI_AIBase::dtorDelete,92,_ZN4ksys3act2ai2AiD0Ev
 0x00000071011de004,AI_AIBase::m25,132,
 0x00000071011de088,AI_AIBase::initChildStates,580,
 0x00000071011de2cc,AI_AIBase::x_0,340,
-0x00000071011de420,AI_AIBase::calcRecursively,156,
+0x00000071011de420,AI_AIBase::calcRecursively,156,_ZN4ksys3act2ai2Ai4calcEv
 0x00000071011de4bc,AI_AIBase::x,76,
 0x00000071011de508,sub_71011DE508,276,
 0x00000071011de61c,sub_71011DE61C,24,
@@ -92268,16 +92268,16 @@
 0x00000071011de7b4,AI_AIBase::doChangeState,440,
 0x00000071011de96c,AI_AIBase::changeState,96,
 0x00000071011de9cc,AI_AIBase::m28,400,
-0x00000071011deb5c,AI_AIBase::m6,72,
-0x00000071011deba4,AI_AIBase::getCurrentChildState,52,
+0x00000071011deb5c,AI_AIBase::m6,72,_ZNK4ksys3act2ai2Ai10isFlag4SetEv
+0x00000071011deba4,AI_AIBase::getCurrentChildState,52,_ZNK4ksys3act2ai2Ai15getCurrentChildEv
 0x00000071011debd8,AI_AIBase::isState,196,
 0x00000071011dec9c,ai::ActorAI::checkAction,188,
-0x00000071011ded58,sub_71011DED58,24,
+0x00000071011ded58,sub_71011DED58,24,_ZN4ksys3act2ai2Ai14updateChildIdxEt
 0x00000071011ded70,AI_AIBase::m22,116,
 0x00000071011dede4,AI_AIBase::m31,224,
 0x00000071011deec4,AI_AIBase::m23,216,
-0x00000071011def9c,AI_AIBase::rtti1,204,
-0x00000071011df068,AI_AIBase::rtti2,92,
+0x00000071011def9c,AI_AIBase::rtti1,204,_ZNK4ksys3act2ai2Ai27checkDerivedRuntimeTypeInfoEPKN4sead15RuntimeTypeInfo9InterfaceE
+0x00000071011df068,AI_AIBase::rtti2,92,_ZNK4ksys3act2ai2Ai18getRuntimeTypeInfoEv
 0x00000071011df0c4,ai::AIs::ctor,28,
 0x00000071011df0e0,sub_71011DF0E0,4,
 0x00000071011df0e4,sub_71011DF0E4,200,
diff --git a/src/KingSystem/ActorSystem/CMakeLists.txt b/src/KingSystem/ActorSystem/CMakeLists.txt
index 509dbb77..dd7a62b8 100644
--- a/src/KingSystem/ActorSystem/CMakeLists.txt
+++ b/src/KingSystem/ActorSystem/CMakeLists.txt
@@ -25,6 +25,8 @@ target_sources(uking PRIVATE
   actAiAction.h
   actAiActionBase.cpp
   actAiActionBase.h
+  actAiAi.cpp
+  actAiAi.h
   actAiClassDef.cpp
   actAiClassDef.h
   actAiParam.cpp
diff --git a/src/KingSystem/ActorSystem/actAiActionBase.h b/src/KingSystem/ActorSystem/actAiActionBase.h
index dafda2c3..4851ecb4 100644
--- a/src/KingSystem/ActorSystem/actAiActionBase.h
+++ b/src/KingSystem/ActorSystem/actAiActionBase.h
@@ -31,8 +31,8 @@ public:
     const char* getName() const;
     bool init(sead::Heap* heap, bool load_map_or_tree_params);
 
-    virtual bool isFinished() const;
     virtual bool isFailed() const;
+    virtual bool isFinished() const;
     virtual bool isFlag4Set() const;
 
     virtual bool m7() { return false; }
@@ -52,13 +52,13 @@ public:
     virtual void getCurrentName(sead::BufferedSafeString* name, ActionBase* parent) const;
     virtual void* m22() { return nullptr; }
     virtual void getParams(ParamNameTypePairs* pairs, bool update_use_count) const;
-    virtual s32 m24() { return 0; }
+    virtual s32 getNumChildren() const { return 0; }
     virtual bool m25() { return true; }
     virtual ActionBase* getCurrentChild() const { return nullptr; }
     virtual bool isAction() const = 0;
     virtual bool reenter(ActionBase* other) { return reenter_(other, false); }
     virtual void postLeave() {}
-    virtual ActionBase* getAction(s32 idx) const { return nullptr; }
+    virtual ActionBase* getChild(s32 idx) const { return nullptr; }
 
 protected:
     enum class Flag : u8 {
@@ -83,8 +83,6 @@ protected:
     u16 mDefinitionIdx;
     u8 mRootIdx;
     sead::TypedBitFlag<Flag> mFlags;
-    u16 mClassIdx;
-    u16 mPrevClassIdx;
 };
 KSYS_CHECK_SIZE_NX150(ActionBase, 0x20);
 
diff --git a/src/KingSystem/ActorSystem/actAiAi.cpp b/src/KingSystem/ActorSystem/actAiAi.cpp
new file mode 100644
index 00000000..d22e5c82
--- /dev/null
+++ b/src/KingSystem/ActorSystem/actAiAi.cpp
@@ -0,0 +1,47 @@
+#include "KingSystem/ActorSystem/actAiAi.h"
+
+namespace ksys::act::ai {
+
+Ai::Ai(const ActionBase::InitArg& arg) : ActionBase(arg) {}
+
+Ai::~Ai() {
+    mChildren.freeBuffer();
+}
+
+void Ai::calc() {
+    calc_();
+
+    auto* child = getCurrentChild();
+    if (child)
+        child->calc();
+
+    if (mPendingChildIdx != InvalidIdx && mChildIdx != mPendingChildIdx) {
+        handlePendingChildChange_();
+        auto* new_child = getCurrentChild();
+        if (new_child)
+            new_child->calc();
+    }
+}
+
+bool Ai::isFlag4Set() const {
+    auto* child = getCurrentChild();
+    if (child)
+        return child->isFlag4Set();
+
+    return mFlags.isOn(Flag::_4);
+}
+
+ActionBase* Ai::getCurrentChild() const {
+    if (mChildIdx == InvalidIdx)
+        return nullptr;
+    return mChildren[mChildIdx];
+}
+
+void Ai::updateChildIdx(u16 new_idx) {
+    const auto prev_idx = mChildIdx;
+    mChildIdx = new_idx;
+    mPrevChildIdx = prev_idx;
+    mPendingChildIdx = InvalidIdx;
+}
+
+}  // namespace ksys::act::ai
diff --git a/src/KingSystem/ActorSystem/actAiAi.h b/src/KingSystem/ActorSystem/actAiAi.h
new file mode 100644
index 00000000..5a3fd9bf
--- /dev/null
+++ b/src/KingSystem/ActorSystem/actAiAi.h
@@ -0,0 +1,45 @@
+#pragma once
+
+#include <container/seadBuffer.h>
+#include "KingSystem/ActorSystem/actAiActionBase.h"
+
+namespace ksys::act::ai {
+
+class Ai : public ActionBase {
+    SEAD_RTTI_OVERRIDE(Ai, ActionBase)
+public:
+    explicit Ai(const InitArg& arg);
+    ~Ai() override;
+
+    bool isFlag4Set() const override;
+    bool reenter_(ActionBase* other, bool x) override;
+    void calc() override;
+    void* m22() override;
+    void getParams(ParamNameTypePairs* pairs, bool update_use_count) const override;
+    s32 getNumChildren() const override { return mChildren.size(); }
+    bool m25() override;
+    ActionBase* getCurrentChild() const override;
+    bool isAction() const override { return false; }
+    bool reenter(ActionBase* other) override;
+    void postLeave() override { updateChildIdx(InvalidIdx); }
+    ActionBase* getChild(s32 idx) const override { return mChildren[idx]; }
+    virtual const char* getPreviousName();
+
+protected:
+    virtual void calc_() {}
+    virtual void handlePendingChildChange_() { changeChildState(mPendingChildIdx); }
+    void updateChildIdx(u16 new_idx);
+    void changeChildState(u16 idx, InlineParamPack* params = nullptr);
+
+    static constexpr u16 InvalidIdx = 0xffff;
+
+    // TODO: give better names to these variables
+    u16 mChildIdx = InvalidIdx;
+    u16 mPrevChildIdx = InvalidIdx;
+    u16 mPendingChildIdx = InvalidIdx;
+    u16 mNewChildIdx = InvalidIdx;
+    sead::Buffer<ActionBase*> mChildren;
+};
+KSYS_CHECK_SIZE_NX150(Ai, 0x38);
+
+}  // namespace ksys::act::ai