diff --git a/data/uking_functions.csv b/data/uking_functions.csv
index 5e756f30..024755d0 100644
--- a/data/uking_functions.csv
+++ b/data/uking_functions.csv
@@ -91875,28 +91875,28 @@
 0x00000071011c0b30,TimerSimple::update,128,
 0x00000071011c0bb0,Timer::update,136,
 0x00000071011c0c38,Timer::ended,48,
-0x00000071011c0c68,sub_71011C0C68,100,
-0x00000071011c0ccc,sub_71011C0CCC,108,
-0x00000071011c0d38,VFR::createInstance,332,
-0x00000071011c0e84,sub_71011C0E84,68,
-0x00000071011c0ec8,sub_71011C0EC8,64,
-0x00000071011c0f08,VFR::init,468,
-0x00000071011c10dc,VFR::__auto1,24,
-0x00000071011c10f4,VFR::clearField29,8,
-0x00000071011c10fc,sub_71011C10FC,544,
-0x00000071011c131c,VFR::x_0,132,
-0x00000071011c13a0,sub_71011C13A0,132,
-0x00000071011c1424,sub_71011C1424,328,
-0x00000071011c156c,VFR::initBeforeStageGenB,316,
-0x00000071011c16a8,VFR::isSlowTime,68,
+0x00000071011c0c68,sub_71011C0C68,100,_ZN4ksys3VFR18SingletonDisposer_D2Ev
+0x00000071011c0ccc,sub_71011C0CCC,108,_ZN4ksys3VFR18SingletonDisposer_D0Ev
+0x00000071011c0d38,VFR::createInstance,332,_ZN4ksys3VFR14createInstanceEPN4sead4HeapE
+0x00000071011c0e84,sub_71011C0E84,68,_ZN4ksys3VFRD1Ev
+0x00000071011c0ec8,sub_71011C0EC8,64,_ZN4ksys3VFRD0Ev
+0x00000071011c0f08,VFR::init,468,_ZN4ksys3VFR4initEjiPN4sead4HeapEj
+0x00000071011c10dc,VFR::__auto1,24,_ZN4ksys3VFR19setIntervalOverrideEj
+0x00000071011c10f4,VFR::clearField29,8,_ZN4ksys3VFR21clearIntervalOverrideEv
+0x00000071011c10fc,sub_71011C10FC,544,_ZN4ksys3VFR14updateIntervalEj
+0x00000071011c131c,VFR::x_0,132,_ZN4ksys3VFR10useBufferBEv
+0x00000071011c13a0,sub_71011C13A0,132,_ZN4ksys3VFR10useBufferAEv
+0x00000071011c1424,sub_71011C1424,328,_ZN4ksys3VFR27setDeltaFromTimeMultipliersEPfjj
+0x00000071011c156c,VFR::initBeforeStageGenB,316,_ZN4ksys3VFR20resetTimeMultipliersEv
+0x00000071011c16a8,VFR::isSlowTime,68,_ZNK4ksys3VFR23hasCustomTimeMultiplierEv
 0x00000071011c16ec,VFR::setSlowTime,136,
 0x00000071011c1774,VFR::endSlowTime,120,
 0x00000071011c17ec,sub_71011C17EC,12,
 0x00000071011c17f8,sub_71011C17F8,184,
 0x00000071011c18b0,sub_71011C18B0,176,
 0x00000071011c1960,sub_71011C1960,200,
-0x00000071011c1a28,VFR::isField29Set,8,
-0x00000071011c1a30,VFR::x,8,
+0x00000071011c1a28,VFR::isField29Set,8,_ZNK4ksys3VFR19hasIntervalOverrideEv
+0x00000071011c1a30,VFR::x,8,_ZNK4ksys3VFR19getIntervalOverrideEv
 0x00000071011c1a38,sub_71011C1A38,44,
 0x00000071011c1a64,sub_71011C1A64,12,
 0x00000071011c1a70,sub_71011C1A70,28,
diff --git a/lib/sead b/lib/sead
index ed983cc4..bb92e59f 160000
--- a/lib/sead
+++ b/lib/sead
@@ -1 +1 @@
-Subproject commit ed983cc42dee614eb4fbc8d71303acec1c7b2c84
+Subproject commit bb92e59f569bf8e865a9710b03015352c137cc29
diff --git a/src/KingSystem/System/CMakeLists.txt b/src/KingSystem/System/CMakeLists.txt
index 42f2dc44..851e291e 100644
--- a/src/KingSystem/System/CMakeLists.txt
+++ b/src/KingSystem/System/CMakeLists.txt
@@ -17,4 +17,6 @@ target_sources(uking PRIVATE
   SystemPauseMgr.h
   Timer.cpp
   Timer.h
+  VFR.cpp
+  VFR.h
 )
diff --git a/src/KingSystem/System/VFR.cpp b/src/KingSystem/System/VFR.cpp
new file mode 100644
index 00000000..71dd2ae6
--- /dev/null
+++ b/src/KingSystem/System/VFR.cpp
@@ -0,0 +1,178 @@
+#include "KingSystem/System/VFR.h"
+#include <mc/seadCoreInfo.h>
+
+namespace ksys {
+
+SEAD_SINGLETON_DISPOSER_IMPL(VFR)
+
+VFR::VFR() {
+    for (int i = 0; i < NumCores; ++i) {
+        mPtrs1[i] = &mFloats1a[i];
+        mDeltaTimes[i] = &mFloats2a[i];
+        mPtrs3[i] = &mFloats3a[i];
+        mDeltaFrames[i] = &mFloats4a[i];
+        mIntervals[i] = &mIntervalA;
+        mIntervalRatios[i] = &mIntervalRatioA;
+    }
+}
+
+VFR::~VFR() {
+    mTimeSpeedMultipliers.freeBuffer();
+}
+
+void VFR::setDelta(u32 core, f32 delta) {
+    delta = sead::Mathf::max(delta, 0.01f);
+    *mPtrs1[core] = delta;
+    *mDeltaTimes[core] = delta * *mIntervalRatios[core];
+    *mPtrs3[core] = delta * mFrameTime;
+    *mDeltaFrames[core] = *mDeltaTimes[core] * mFrameTime;
+}
+
+void VFR::setDeltaFromTimeMultipliers(u32 core, const sead::BitFlag32& mask) {
+    f32 min = 1.0;
+    for (s32 i = 0; i < mTimeSpeedMultipliers.size(); ++i) {
+        if (mask.isOnBit(i))
+            min = sead::Mathf::min(min, mTimeSpeedMultipliers[i].value);
+    }
+    setDelta(core, min);
+}
+
+void VFR::resetTimeMultipliers() {
+    for (auto& entry : mTimeSpeedMultipliers) {
+        entry.value = 1.0;
+        entry.target_value = 1.0;
+        entry.is_custom = false;
+    }
+    x_1();
+}
+
+void VFR::x_1() {
+    setDeltaFromTimeMultipliers(0, mMask);
+
+    for (s32 i = 0; i < NumCores; ++i) {
+        mFloats2a[i] = mFloats2a[0];
+        mFloats3a[i] = mFloats3a[0];
+        mFloats4a[i] = mFloats4a[0];
+        mFloats1a[i] = mFloats1a[0];
+    }
+}
+
+void VFR::copyAtoB() {
+    for (s32 i = 0; i < NumCores; ++i) {
+        mFloats1b[i] = mFloats1a[i];
+        mFloats2b[i] = mFloats2a[i];
+        mFloats3b[i] = mFloats3a[i];
+        mFloats4b[i] = mFloats4a[i];
+        mIntervalB = mIntervalA;
+        mIntervalRatioB = mIntervalRatioA;
+    }
+}
+
+void VFR::init(u32 interval, int num_speed_multipliers, sead::Heap* heap, u32 mask) {
+    mInterval = interval;
+    mFrameRate = 60 / interval;
+    mIntervalA = interval;
+    mIntervalB = interval;
+    mFrameTime = 1.0f / mFrameRate;
+    mTimeSpeedMultipliers.allocBufferAssert(num_speed_multipliers, heap);
+    mMask = mask;
+    x_1();
+    copyAtoB();
+}
+
+void VFR::setIntervalOverride(u32 interval) {
+    if (!mHasIntervalOverride) {
+        mHasIntervalOverride = true;
+        mIntervalOverride = interval;
+    }
+}
+
+void VFR::clearIntervalOverride() {
+    mHasIntervalOverride = false;
+}
+
+bool VFR::hasIntervalOverride() const {
+    return mHasIntervalOverride;
+}
+
+u32 VFR::getIntervalOverride() const {
+    return mIntervalOverride;
+}
+
+VFR::TimeSpeedMultiplier::TimeSpeedMultiplier() = default;
+
+VFR::TimeSpeedMultiplier::~TimeSpeedMultiplier() = default;
+
+void VFR::TimeSpeedMultiplier::update(f32 multiplier) {
+    if (target_value == value)
+        return;
+
+    is_custom = target_value != 1.0;
+    if (target_value < value) {
+        value = target_value;
+    } else {
+        sead::Mathf::chase(&value, target_value, sead::Mathf::max(value * multiplier, 0.01));
+    }
+}
+
+void VFR::updateInterval(u32 new_interval) {
+    copyAtoB();
+
+    if (mHasIntervalOverride)
+        new_interval = mIntervalOverride;
+
+    if (new_interval != 0 && mIntervalA != new_interval) {
+        mIntervalA = new_interval;
+        mHasIntervalChanged = true;
+        mNewIntervalRatio = f32(new_interval) * (1.0f / mInterval);
+    } else {
+        mHasIntervalChanged = false;
+    }
+
+    if (mNewIntervalRatio != mIntervalRatioA)
+        mIntervalRatioA = mNewIntervalRatio;
+
+    for (s32 i = 0; i < mTimeSpeedMultipliers.size(); ++i) {
+        mTimeSpeedMultipliers[i].update(mIntervalRatioA);
+    }
+
+    x_1();
+}
+
+void VFR::useBufferB() {
+    const u32 core = sead::CoreInfo::getCurrentCoreId();
+    mPtrs1[core] = &mFloats1b[core];
+    mDeltaTimes[core] = &mFloats2b[core];
+    mPtrs3[core] = &mFloats3b[core];
+    mDeltaFrames[core] = &mFloats4b[core];
+    mIntervals[core] = &mIntervalB;
+    mIntervalRatios[core] = &mIntervalRatioB;
+}
+
+void VFR::useBufferA() {
+    const u32 core = sead::CoreInfo::getCurrentCoreId();
+    mPtrs1[core] = &mFloats1a[core];
+    mDeltaTimes[core] = &mFloats2a[core];
+    mPtrs3[core] = &mFloats3a[core];
+    mDeltaFrames[core] = &mFloats4a[core];
+    mIntervals[core] = &mIntervalA;
+    mIntervalRatios[core] = &mIntervalRatioA;
+}
+
+f32 VFR::setDeltaFromTimeMultipliers(f32* value, u32 include_mask, u32 exclude_mask) {
+    const u32 core = sead::CoreInfo::getCurrentCoreId();
+    *value = *mPtrs1[core];
+    const f32 delta = *mDeltaTimes[core];
+    setDeltaFromTimeMultipliers(core, (mMask.getDirect() | include_mask) & ~exclude_mask);
+    return delta;
+}
+
+bool VFR::hasCustomTimeMultiplier() const {
+    for (const auto& entry : mTimeSpeedMultipliers) {
+        if (entry.value != 1.0)
+            return true;
+    }
+    return false;
+}
+
+}  // namespace ksys
diff --git a/src/KingSystem/System/VFR.h b/src/KingSystem/System/VFR.h
new file mode 100644
index 00000000..f3626f96
--- /dev/null
+++ b/src/KingSystem/System/VFR.h
@@ -0,0 +1,106 @@
+#pragma once
+
+#include <basis/seadTypes.h>
+#include <container/seadBuffer.h>
+#include <container/seadSafeArray.h>
+#include <heap/seadDisposer.h>
+#include <prim/seadBitFlag.h>
+#include "KingSystem/Utils/Types.h"
+
+namespace ksys {
+
+class VFR {
+    SEAD_SINGLETON_DISPOSER(VFR)
+    VFR();
+    virtual ~VFR();
+
+public:
+    struct TimeSpeedMultiplier {
+        TimeSpeedMultiplier();
+        ~TimeSpeedMultiplier();
+        TimeSpeedMultiplier(const TimeSpeedMultiplier&) = default;
+        TimeSpeedMultiplier(TimeSpeedMultiplier&&) = default;
+        TimeSpeedMultiplier& operator=(const TimeSpeedMultiplier&) = default;
+        TimeSpeedMultiplier& operator=(TimeSpeedMultiplier&&) = default;
+
+        void update(f32 multiplier);
+
+        bool is_custom = false;
+        f32 value = 1.0;
+        f32 target_value = 1.0;
+    };
+
+    void init(u32 interval, int num_speed_multipliers, sead::Heap* heap, u32 mask);
+
+    void setIntervalOverride(u32 interval);
+    void clearIntervalOverride();
+    bool hasIntervalOverride() const;
+    u32 getIntervalOverride() const;
+
+    void updateInterval(u32 new_interval);
+
+    void useBufferB();
+    void useBufferA();
+
+    f32 setDeltaFromTimeMultipliers(f32* value, u32 include_mask, u32 exclude_mask);
+    void resetTimeMultipliers();
+    bool hasCustomTimeMultiplier() const;
+    // TODO: requires ksys::Sound
+    void setTimeMultiplier(u32 idx, f32 multiplier);
+    // TODO: requires ksys::Sound
+    void resetTimeMultiplier(u32 idx);
+
+private:
+    struct TimeSpeedMultipliers : sead::Buffer<TimeSpeedMultiplier> {
+        TimeSpeedMultipliers() {
+            mBuffer = nullptr;
+            mSize = 0;
+        }
+    };
+
+    void setDelta(u32 core, f32 delta);
+    void setDeltaFromTimeMultipliers(u32 core, const sead::BitFlag32& mask);
+    void x_1();
+    void copyAtoB();
+
+    bool mHasIntervalChanged = false;
+    bool mHasIntervalOverride = false;
+    u32 mIntervalOverride = 1;
+    f32 mNewIntervalRatio = 1.0;
+    u32 mIntervalA = 1;
+    u32 mIntervalB = 1;
+    f32 mIntervalRatioA = 1.0;
+    f32 mIntervalRatioB = 1.0;
+
+    static constexpr int NumCores = 3;
+
+    sead::SafeArray<u32*, NumCores> mIntervals;
+    sead::SafeArray<f32*, NumCores> mIntervalRatios;
+
+    TimeSpeedMultipliers mTimeSpeedMultipliers;
+    sead::BitFlag32 mMask = 0xffffffff;
+
+    sead::SafeArray<f32, NumCores> mFloats1a{};
+    sead::SafeArray<f32, NumCores> mFloats2a{};
+    sead::SafeArray<f32, NumCores> mFloats3a{};
+    sead::SafeArray<f32, NumCores> mFloats4a{};
+
+    sead::SafeArray<f32, NumCores> mFloats1b{};
+    sead::SafeArray<f32, NumCores> mFloats2b{};
+    sead::SafeArray<f32, NumCores> mFloats3b{};
+    sead::SafeArray<f32, NumCores> mFloats4b{};
+
+    sead::SafeArray<f32*, NumCores> mPtrs1;
+    sead::SafeArray<f32*, NumCores> mDeltaTimes;
+    sead::SafeArray<f32*, NumCores> mPtrs3;
+    sead::SafeArray<f32*, NumCores> mDeltaFrames;
+    /// Present interval.
+    u32 mInterval = 1;
+    /// Frames per second.
+    u32 mFrameRate = 60;
+    /// Second per frame.
+    f32 mFrameTime = 1.0 / 60.0;
+};
+KSYS_CHECK_SIZE_NX150(VFR, 0x160);
+
+}  // namespace ksys