diff --git a/feature/session/src/main/java/io/github/droidkaigi/confsched2019/session/ui/item/ServiceSessionItem.kt b/feature/session/src/main/java/io/github/droidkaigi/confsched2019/session/ui/item/ServiceSessionItem.kt
index 2b41fae0f..bcee9b8be 100644
--- a/feature/session/src/main/java/io/github/droidkaigi/confsched2019/session/ui/item/ServiceSessionItem.kt
+++ b/feature/session/src/main/java/io/github/droidkaigi/confsched2019/session/ui/item/ServiceSessionItem.kt
@@ -5,6 +5,7 @@ import androidx.navigation.NavDirections
 import com.squareup.inject.assisted.Assisted
 import com.squareup.inject.assisted.AssistedInject
 import com.xwray.groupie.databinding.BindableItem
+import io.github.droidkaigi.confsched2019.item.EqualableContentsProvider
 import io.github.droidkaigi.confsched2019.model.ServiceSession
 import io.github.droidkaigi.confsched2019.model.defaultLang
 import io.github.droidkaigi.confsched2019.session.R
@@ -19,7 +20,7 @@ class ServiceSessionItem @AssistedInject constructor(
     val sessionContentsActionCreator: SessionContentsActionCreator
 ) : BindableItem<ItemServiceSessionBinding>(
     session.id.hashCode().toLong()
-), SessionItem {
+), SessionItem, EqualableContentsProvider {
     val serviceSession get() = session
 
     @AssistedInject.Factory
@@ -63,18 +64,13 @@ class ServiceSessionItem @AssistedInject constructor(
 
     override fun getLayout(): Int = R.layout.item_service_session
 
-    override fun equals(other: Any?): Boolean {
-        if (this === other) return true
-        if (javaClass != other?.javaClass) return false
-
-        other as ServiceSessionItem
+    override fun providerEqualableContents(): Array<*> = arrayOf(session)
 
-        if (session != other.session) return false
-
-        return true
+    override fun equals(other: Any?): Boolean {
+        return isSameContents(other)
     }
 
     override fun hashCode(): Int {
-        return session.hashCode()
+        return contentsHash()
     }
 }
diff --git a/feature/session/src/main/java/io/github/droidkaigi/confsched2019/session/ui/item/SpeakerItem.kt b/feature/session/src/main/java/io/github/droidkaigi/confsched2019/session/ui/item/SpeakerItem.kt
index 0e64c402f..7f59272f6 100644
--- a/feature/session/src/main/java/io/github/droidkaigi/confsched2019/session/ui/item/SpeakerItem.kt
+++ b/feature/session/src/main/java/io/github/droidkaigi/confsched2019/session/ui/item/SpeakerItem.kt
@@ -8,6 +8,7 @@ import com.squareup.inject.assisted.Assisted
 import com.squareup.inject.assisted.AssistedInject
 import com.squareup.picasso.Picasso
 import com.xwray.groupie.databinding.BindableItem
+import io.github.droidkaigi.confsched2019.item.EqualableContentsProvider
 import io.github.droidkaigi.confsched2019.model.Speaker
 import io.github.droidkaigi.confsched2019.session.R
 import io.github.droidkaigi.confsched2019.session.databinding.ItemSpeakerBinding
@@ -18,7 +19,8 @@ class SpeakerItem @AssistedInject constructor(
     @Assisted val clickNavDirection: NavDirections,
     @Assisted val query: String?,
     val navController: NavController
-) : BindableItem<ItemSpeakerBinding>(speaker.id.hashCode().toLong()) {
+) : BindableItem<ItemSpeakerBinding>(speaker.id.hashCode().toLong()),
+    EqualableContentsProvider {
     @AssistedInject.Factory
     interface Factory {
         fun create(
@@ -64,19 +66,17 @@ class SpeakerItem @AssistedInject constructor(
         }
     }
 
-    override fun equals(other: Any?): Boolean {
-        if (this === other) return true
-        if (javaClass != other?.javaClass) return false
-
-        other as SpeakerItem
+    override fun providerEqualableContents(): Array<*> = arrayOf(speaker)
 
-        if (speaker != other.speaker) return false
-        if (query != other.query) return false
+    override fun isTextHighlightNeedUpdate() = query?.let {
+        speaker.name.toLowerCase().contains(it.toLowerCase())
+    } ?: false
 
-        return true
+    override fun equals(other: Any?): Boolean {
+        return isSameContents(other)
     }
 
     override fun hashCode(): Int {
-        return speaker.hashCode() + query.hashCode()
+        return contentsHash()
     }
 }
diff --git a/feature/session/src/main/java/io/github/droidkaigi/confsched2019/session/ui/item/SpeechSessionItem.kt b/feature/session/src/main/java/io/github/droidkaigi/confsched2019/session/ui/item/SpeechSessionItem.kt
index e99fbd912..9c06e84fb 100644
--- a/feature/session/src/main/java/io/github/droidkaigi/confsched2019/session/ui/item/SpeechSessionItem.kt
+++ b/feature/session/src/main/java/io/github/droidkaigi/confsched2019/session/ui/item/SpeechSessionItem.kt
@@ -18,6 +18,7 @@ import com.squareup.inject.assisted.AssistedInject
 import com.squareup.picasso.Picasso
 import com.squareup.picasso.Target
 import com.xwray.groupie.databinding.BindableItem
+import io.github.droidkaigi.confsched2019.item.EqualableContentsProvider
 import io.github.droidkaigi.confsched2019.model.Speaker
 import io.github.droidkaigi.confsched2019.model.SpeechSession
 import io.github.droidkaigi.confsched2019.model.defaultLang
@@ -40,7 +41,7 @@ class SpeechSessionItem @AssistedInject constructor(
     val sessionContentsActionCreator: SessionContentsActionCreator
 ) : BindableItem<ItemSessionBinding>(
     session.id.hashCode().toLong()
-), SessionItem {
+), SessionItem, EqualableContentsProvider {
     val speechSession get() = session
 
     @AssistedInject.Factory
@@ -199,19 +200,24 @@ class SpeechSessionItem @AssistedInject constructor(
 
     override fun getLayout(): Int = R.layout.item_session
 
-    override fun equals(other: Any?): Boolean {
-        if (this === other) return true
-        if (javaClass != other?.javaClass) return false
-
-        other as SpeechSessionItem
+    override fun providerEqualableContents(): Array<*> = arrayOf(session)
 
-        if (session != other.session) return false
-        if (query == null || other.query == null || query != other.query) return false
+    override fun isTextHighlightNeedUpdate() = query?.let {
+        when {
+            session.title.getByLang(defaultLang()).toLowerCase()
+                .contains(query.toLowerCase()) -> true
+            session.speakers.find {
+                it.name.toLowerCase().contains(query.toLowerCase())
+            } != null -> true
+            else -> false
+        }
+    } ?: false
 
-        return true
+    override fun equals(other: Any?): Boolean {
+        return isSameContents(other)
     }
 
     override fun hashCode(): Int {
-        return session.hashCode() + query.hashCode()
+        return contentsHash()
     }
 }
diff --git a/feature/session/src/main/java/io/github/droidkaigi/confsched2019/session/ui/item/TabularServiceSessionItem.kt b/feature/session/src/main/java/io/github/droidkaigi/confsched2019/session/ui/item/TabularServiceSessionItem.kt
index 392c0778f..908c63c58 100644
--- a/feature/session/src/main/java/io/github/droidkaigi/confsched2019/session/ui/item/TabularServiceSessionItem.kt
+++ b/feature/session/src/main/java/io/github/droidkaigi/confsched2019/session/ui/item/TabularServiceSessionItem.kt
@@ -6,6 +6,7 @@ import androidx.navigation.NavDirections
 import com.squareup.inject.assisted.Assisted
 import com.squareup.inject.assisted.AssistedInject
 import com.xwray.groupie.databinding.BindableItem
+import io.github.droidkaigi.confsched2019.item.EqualableContentsProvider
 import io.github.droidkaigi.confsched2019.model.ServiceSession
 import io.github.droidkaigi.confsched2019.model.defaultLang
 import io.github.droidkaigi.confsched2019.session.R
@@ -17,7 +18,7 @@ class TabularServiceSessionItem @AssistedInject constructor(
     private val navController: NavController
 ) : BindableItem<ItemTabularServiceSessionBinding>(
     session.id.hashCode().toLong()
-), SessionItem {
+), SessionItem, EqualableContentsProvider {
 
     @AssistedInject.Factory
     interface Factory {
@@ -46,18 +47,13 @@ class TabularServiceSessionItem @AssistedInject constructor(
 
     override fun getLayout() = R.layout.item_tabular_service_session
 
-    override fun equals(other: Any?): Boolean {
-        if (this === other) return true
-        if (javaClass != other?.javaClass) return false
-
-        other as TabularServiceSessionItem
+    override fun providerEqualableContents(): Array<*> = arrayOf(session)
 
-        if (session != other.session) return false
-
-        return true
+    override fun equals(other: Any?): Boolean {
+        return isSameContents(other)
     }
 
     override fun hashCode(): Int {
-        return session.hashCode()
+        return contentsHash()
     }
 }
diff --git a/feature/session/src/main/java/io/github/droidkaigi/confsched2019/session/ui/item/TabularSpeechSessionItem.kt b/feature/session/src/main/java/io/github/droidkaigi/confsched2019/session/ui/item/TabularSpeechSessionItem.kt
index ef5c2f19a..b4fc9d207 100644
--- a/feature/session/src/main/java/io/github/droidkaigi/confsched2019/session/ui/item/TabularSpeechSessionItem.kt
+++ b/feature/session/src/main/java/io/github/droidkaigi/confsched2019/session/ui/item/TabularSpeechSessionItem.kt
@@ -12,6 +12,7 @@ import com.squareup.picasso.Picasso
 import com.xwray.groupie.GroupAdapter
 import com.xwray.groupie.databinding.BindableItem
 import com.xwray.groupie.databinding.ViewHolder
+import io.github.droidkaigi.confsched2019.item.EqualableContentsProvider
 import io.github.droidkaigi.confsched2019.model.Speaker
 import io.github.droidkaigi.confsched2019.model.SpeechSession
 import io.github.droidkaigi.confsched2019.model.defaultLang
@@ -26,7 +27,7 @@ class TabularSpeechSessionItem @AssistedInject constructor(
     private val navController: NavController
 ) : BindableItem<ItemTabularSpeechSessionBinding>(
     session.id.hashCode().toLong()
-), SessionItem {
+), SessionItem, EqualableContentsProvider {
 
     @AssistedInject.Factory
     interface Factory {
@@ -82,19 +83,14 @@ class TabularSpeechSessionItem @AssistedInject constructor(
 
     override fun getLayout() = R.layout.item_tabular_speech_session
 
-    override fun equals(other: Any?): Boolean {
-        if (this === other) return true
-        if (javaClass != other?.javaClass) return false
-
-        other as TabularSpeechSessionItem
+    override fun providerEqualableContents(): Array<*> = arrayOf(session)
 
-        if (session != other.session) return false
-
-        return true
+    override fun equals(other: Any?): Boolean {
+        return isSameContents(other)
     }
 
     override fun hashCode(): Int {
-        return session.hashCode()
+        return contentsHash()
     }
 
     private class SpeakerIconItem(
diff --git a/frontendcomponent/androidcomponent/src/main/java/io/github/droidkaigi/confsched2019/item/EqualableContentsProvider.kt b/frontendcomponent/androidcomponent/src/main/java/io/github/droidkaigi/confsched2019/item/EqualableContentsProvider.kt
new file mode 100644
index 000000000..9bea27a52
--- /dev/null
+++ b/frontendcomponent/androidcomponent/src/main/java/io/github/droidkaigi/confsched2019/item/EqualableContentsProvider.kt
@@ -0,0 +1,28 @@
+package io.github.droidkaigi.confsched2019.item
+
+import java.util.Arrays
+
+interface EqualableContentsProvider {
+    fun providerEqualableContents(): Array<*>
+
+    override fun equals(other: Any?): Boolean
+
+    override fun hashCode(): Int
+
+    fun isTextHighlightNeedUpdate(): Boolean {
+        return false
+    }
+
+    fun isSameContents(other: Any?): Boolean {
+        other ?: return false
+        if (other !is EqualableContentsProvider) return false
+        if (other::class != this::class) return false
+        if (isTextHighlightNeedUpdate()) return false
+        if (other.isTextHighlightNeedUpdate()) return false
+        return other.providerEqualableContents().contentDeepEquals(this.providerEqualableContents())
+    }
+
+    fun contentsHash(): Int {
+        return Arrays.deepHashCode(arrayOf(this::class, this.providerEqualableContents()))
+    }
+}