diff --git a/app/build.gradle b/app/build.gradle
index e9b0320..a4c5b6a 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -136,7 +136,6 @@ dependencies {
     implementation libs.converter.scalars
 
     implementation libs.logger
-    implementation libs.eventbus
 }
 
 // OpenAPI Generator Configuration
diff --git a/app/proguard-rules.pro b/app/proguard-rules.pro
index fb53bc4..74f1594 100644
--- a/app/proguard-rules.pro
+++ b/app/proguard-rules.pro
@@ -20,12 +20,12 @@
 -if interface * { @retrofit2.http.* <methods>; }
 -keep,allowobfuscation interface <1>
 
-## EventBus
+## EventBus (Flow-based)
 -keepattributes *Annotation*
 -keepclassmembers class * {
-    @org.greenrobot.eventbus.Subscribe <methods>;
+    @info.nukoneko.cuc.android.kidspos.di.Subscribe <methods>;
 }
--keep enum org.greenrobot.eventbus.ThreadMode { *; }
+-keep enum info.nukoneko.cuc.android.kidspos.di.ThreadMode { *; }
 
 #------ Gson -------
 -keep class info.nukoneko.cuc.android.kidspos.entity.** { *; }
diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/App.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/App.kt
index ecfe211..826f83f 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/App.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/App.kt
@@ -10,8 +10,8 @@ import info.nukoneko.cuc.android.kidspos.di.module.viewModelModule
 import info.nukoneko.cuc.android.kidspos.event.EventBus
 import info.nukoneko.cuc.android.kidspos.event.SystemEvent
 import okhttp3.Interceptor
-import org.greenrobot.eventbus.Subscribe
-import org.greenrobot.eventbus.ThreadMode
+import info.nukoneko.cuc.android.kidspos.di.Subscribe
+import info.nukoneko.cuc.android.kidspos.di.ThreadMode
 import org.koin.android.ext.android.inject
 import org.koin.android.ext.koin.androidContext
 import org.koin.core.context.startKoin
diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/di/EventBusImpl.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/di/EventBusImpl.kt
index 06dc23e..5efe254 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/di/EventBusImpl.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/di/EventBusImpl.kt
@@ -2,18 +2,91 @@ package info.nukoneko.cuc.android.kidspos.di
 
 import info.nukoneko.cuc.android.kidspos.event.Event
 import info.nukoneko.cuc.android.kidspos.event.EventBus
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.SharedFlow
+import kotlinx.coroutines.flow.asSharedFlow
+import kotlinx.coroutines.launch
+import java.lang.reflect.Method
+import java.util.concurrent.ConcurrentHashMap
 
 class EventBusImpl : EventBus {
-    private val bus = org.greenrobot.eventbus.EventBus.getDefault()
+    private val scope = CoroutineScope(SupervisorJob() + Dispatchers.Main.immediate)
+    private val _events = MutableSharedFlow<Event>(replay = 0, extraBufferCapacity = 64)
+    private val events: SharedFlow<Event> = _events.asSharedFlow()
+    
+    private val subscribers = ConcurrentHashMap<Any, SubscriberInfo>()
+
+    override fun post(event: Event) {
+        scope.launch {
+            _events.emit(event)
+        }
+    }
+
     override fun register(obj: Any?) {
-        bus.register(obj)
+        obj?.let { subscriber ->
+            val methods = findSubscribeMethods(subscriber::class.java)
+            if (methods.isNotEmpty()) {
+                val job = scope.launch {
+                    events.collect { event ->
+                        if (subscribers.containsKey(subscriber)) {
+                            methods.forEach { method ->
+                                val parameterType = method.parameterTypes.firstOrNull()
+                                if (parameterType?.isAssignableFrom(event::class.java) == true) {
+                                    try {
+                                        method.isAccessible = true
+                                        method.invoke(subscriber, event)
+                                    } catch (e: Exception) {
+                                        e.printStackTrace()
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+                subscribers[subscriber] = SubscriberInfo(methods, job)
+            }
+        }
     }
 
     override fun unregister(obj: Any?) {
-        bus.unregister(obj)
+        obj?.let { subscriber ->
+            subscribers.remove(subscriber)?.job?.cancel()
+        }
     }
 
-    override fun post(event: Event) {
-        bus.post(event)
+    private fun findSubscribeMethods(clazz: Class<*>): List<Method> {
+        val methods = mutableListOf<Method>()
+        var currentClass: Class<*>? = clazz
+        
+        while (currentClass != null) {
+            currentClass.declaredMethods.forEach { method ->
+                if (method.isAnnotationPresent(Subscribe::class.java)) {
+                    if (method.parameterTypes.size == 1 && 
+                        Event::class.java.isAssignableFrom(method.parameterTypes[0])) {
+                        methods.add(method)
+                    }
+                }
+            }
+            currentClass = currentClass.superclass
+        }
+        
+        return methods
     }
-}
\ No newline at end of file
+
+    private data class SubscriberInfo(
+        val methods: List<Method>,
+        val job: Job
+    )
+}
+
+@Target(AnnotationTarget.FUNCTION)
+@Retention(AnnotationRetention.RUNTIME)
+annotation class Subscribe(val threadMode: ThreadMode = ThreadMode.MAIN)
+
+enum class ThreadMode {
+    MAIN
+}
diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainViewModel.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainViewModel.kt
index 5b67aaf..06bdb8f 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainViewModel.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainViewModel.kt
@@ -15,8 +15,8 @@ import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
-import org.greenrobot.eventbus.Subscribe
-import org.greenrobot.eventbus.ThreadMode
+import info.nukoneko.cuc.android.kidspos.di.Subscribe
+import info.nukoneko.cuc.android.kidspos.di.ThreadMode
 import java.io.IOException
 import kotlin.coroutines.CoroutineContext
 
diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/itemlist/ItemListViewModel.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/itemlist/ItemListViewModel.kt
index 1491fc1..fcdeed5 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/itemlist/ItemListViewModel.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/itemlist/ItemListViewModel.kt
@@ -12,8 +12,8 @@ import info.nukoneko.cuc.android.kidspos.event.BarcodeEvent
 import info.nukoneko.cuc.android.kidspos.event.EventBus
 import info.nukoneko.cuc.android.kidspos.event.SystemEvent
 import info.nukoneko.cuc.android.kidspos.util.Mode
-import org.greenrobot.eventbus.Subscribe
-import org.greenrobot.eventbus.ThreadMode
+import info.nukoneko.cuc.android.kidspos.di.Subscribe
+import info.nukoneko.cuc.android.kidspos.di.ThreadMode
 
 class ItemListViewModel(
     private val config: GlobalConfig,
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 293e3a2..b40e709 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -56,7 +56,6 @@ retrofit-client = { module = "com.squareup.retrofit2:retrofit", version.ref = "r
 retrofit-converter-serialization = { module = "com.jakewharton.retrofit:retrofit2-kotlinx-serialization-converter", version.ref = "retrofit-kotlin-serialization-converter" }
 
 logger = { module = "com.orhanobut:logger", version = "2.2.0" }
-eventbus = { module = "org.greenrobot:eventbus", version = "3.2.0" }
 
 [plugins]
 android-application = { id = "com.android.application", version.ref = "android-gradle-plugin" }