diff --git a/app/src/main/java/jp/juggler/subwaytooter/ColumnViewHolder.kt b/app/src/main/java/jp/juggler/subwaytooter/ColumnViewHolder.kt
index d5a4d6ca..794b77b2 100644
--- a/app/src/main/java/jp/juggler/subwaytooter/ColumnViewHolder.kt
+++ b/app/src/main/java/jp/juggler/subwaytooter/ColumnViewHolder.kt
@@ -1178,7 +1178,7 @@ class ColumnViewHolder(
 		tvColumnContext.text = if(nickname != null && nickname.isNotEmpty())
 			nickname
 		else
-			acct
+			column.access_info.prettyAcct
 		
 		
 		tvColumnContext.setTextColor(
diff --git a/app/src/main/java/jp/juggler/subwaytooter/dialog/LoginForm.kt b/app/src/main/java/jp/juggler/subwaytooter/dialog/LoginForm.kt
index 812b2d8b..5a45986b 100644
--- a/app/src/main/java/jp/juggler/subwaytooter/dialog/LoginForm.kt
+++ b/app/src/main/java/jp/juggler/subwaytooter/dialog/LoginForm.kt
@@ -14,6 +14,7 @@ import jp.juggler.util.LogCategory
 import jp.juggler.util.showToast
 import java.io.BufferedReader
 import java.io.InputStreamReader
+import java.net.IDN
 import java.util.*
 
 object LoginForm {
@@ -111,31 +112,35 @@ object LoginForm {
 					showToast(activity, true, R.string.instance_not_need_slash)
 				
 				else -> {
+					val instanceAscii = IDN.toASCII(instance,IDN.ALLOW_UNASSIGNED)
 					val actionPos = spAction.selectedItemPosition
 					when(val action = Action.values().find { it.pos == actionPos }) {
 						null -> {
 						} // will no happened
-						else -> onClickOk(dialog, instance, action)
+						else -> onClickOk(dialog, instanceAscii, action)
 					}
 				}
 			}
 		}
 		view.findViewById<View>(R.id.btnCancel).setOnClickListener { dialog.cancel() }
 		
-		val instance_list = ArrayList<String>()
-		try {
-			activity.resources.openRawResource(R.raw.server_list).use { inStream ->
-				val br = BufferedReader(InputStreamReader(inStream, "UTF-8"))
-				while(true) {
-					val s : String =
-						br.readLine()?.trim { it <= ' ' }?.toLowerCase(Locale.JAPAN) ?: break
-					if(s.isNotEmpty()) instance_list.add(s)
+		val instance_list = HashSet<String>().apply{
+			try {
+				activity.resources.openRawResource(R.raw.server_list).use { inStream ->
+					val br = BufferedReader(InputStreamReader(inStream, "UTF-8"))
+					while(true) {
+						val s : String =
+							br.readLine()?.trim { it <= ' ' }?.toLowerCase(Locale.JAPAN) ?: break
+						if(s.isEmpty()) continue
+						add(s)
+						add(IDN.toASCII(s,IDN.ALLOW_UNASSIGNED))
+						add(IDN.toUnicode(s,IDN.ALLOW_UNASSIGNED))
+					}
 				}
+			} catch(ex : Throwable) {
+				log.trace(ex)
 			}
-			instance_list.sort()
-		} catch(ex : Throwable) {
-			log.trace(ex)
-		}
+		}.toList().sorted()
 		
 		val adapter = object : ArrayAdapter<String>(
 			activity, R.layout.lv_spinner_dropdown, ArrayList()
@@ -146,23 +151,22 @@ object LoginForm {
 					return value as String
 				}
 				
-				override fun performFiltering(constraint : CharSequence?) : FilterResults {
-					val result = FilterResults()
-					if(constraint?.isNotEmpty() == true) {
-						val key = constraint.toString().toLowerCase(Locale.JAPAN)
-						// suggestions リストは毎回生成する必要がある。publishResultsと同時にアクセスされる場合がある
-						val suggestions = StringArray()
-						for(s in instance_list) {
-							if(s.contains(key)) {
-								suggestions.add(s)
-								if(suggestions.size >= 20) break
+				override fun performFiltering(constraint : CharSequence?) : FilterResults =
+					FilterResults().also { result ->
+						if(constraint?.isNotEmpty() == true) {
+							val key = constraint.toString().toLowerCase(Locale.JAPAN)
+							// suggestions リストは毎回生成する必要がある。publishResultsと同時にアクセスされる場合がある
+							val suggestions = StringArray()
+							for(s in instance_list) {
+								if(s.contains(key)) {
+									suggestions.add(s)
+									if(suggestions.size >= 20) break
+								}
 							}
+							result.values = suggestions
+							result.count = suggestions.size
 						}
-						result.values = suggestions
-						result.count = suggestions.size
 					}
-					return result
-				}
 				
 				override fun publishResults(
 					constraint : CharSequence?,
diff --git a/app/src/main/java/jp/juggler/subwaytooter/table/SavedAccount.kt b/app/src/main/java/jp/juggler/subwaytooter/table/SavedAccount.kt
index 4229f70b..40332422 100644
--- a/app/src/main/java/jp/juggler/subwaytooter/table/SavedAccount.kt
+++ b/app/src/main/java/jp/juggler/subwaytooter/table/SavedAccount.kt
@@ -16,6 +16,7 @@ import jp.juggler.subwaytooter.api.entity.TootNotification
 import jp.juggler.subwaytooter.api.entity.TootVisibility
 import jp.juggler.subwaytooter.util.LinkHelper
 import jp.juggler.util.*
+import java.net.IDN
 import java.util.*
 import java.util.regex.Pattern
 
@@ -69,13 +70,18 @@ class SavedAccount(
 	var last_subscription_error : String? = null
 	var last_push_endpoint : String? = null
 	
+	val prettyAcct :String
+	
 	init {
 		val pos = acct.indexOf('@')
 		if(pos == - 1) {
 			this.username = acct
+			prettyAcct = acct
 		} else {
 			this.username = acct.substring(0, pos)
+			prettyAcct = username+"@"+IDN.toUnicode(acct.substring(pos+1),IDN.ALLOW_UNASSIGNED)
 		}
+		
 		if(username.isEmpty()) throw RuntimeException("missing username in acct")
 		
 		this.host = if(hostArg != null && hostArg.isNotEmpty()) {
diff --git a/app/src/main/res/raw/server_list.txt b/app/src/main/res/raw/server_list.txt
index 7fada83d..0ec61847 100644
--- a/app/src/main/res/raw/server_list.txt
+++ b/app/src/main/res/raw/server_list.txt
@@ -10073,3 +10073,4 @@ zuyadon.tk
 zwitscher.l-uni.co
 zxc.st
 zzz.cat
+xn--3-pfuzbe6htf.juggler.jp
diff --git a/app/src/test/java/jp/juggler/subwaytooter/TestIDN.kt b/app/src/test/java/jp/juggler/subwaytooter/TestIDN.kt
new file mode 100644
index 00000000..25556c62
--- /dev/null
+++ b/app/src/test/java/jp/juggler/subwaytooter/TestIDN.kt
@@ -0,0 +1,28 @@
+package jp.juggler.subwaytooter
+
+import org.junit.Test
+import java.net.IDN
+import kotlin.test.assertEquals
+
+class TestIDN {
+	
+	@Test
+	@Throws(Exception::class)
+	fun testIDN() {
+		// normal conversion
+		assertEquals("xn--3-pfuzbe6htf.juggler.jp", IDN.toASCII("マストドン3.juggler.jp",IDN.ALLOW_UNASSIGNED))
+		assertEquals("マストドン3.juggler.jp", IDN.toUnicode("xn--3-pfuzbe6htf.juggler.jp",IDN.ALLOW_UNASSIGNED))
+		
+		// not IDN domain
+		assertEquals("mastodon.juggler.jp", IDN.toASCII("mastodon.juggler.jp",IDN.ALLOW_UNASSIGNED))
+		assertEquals("mastodon.juggler.jp", IDN.toUnicode("mastodon.juggler.jp",IDN.ALLOW_UNASSIGNED))
+		
+		// 既に変換済みの引数
+		assertEquals("xn--3-pfuzbe6htf.juggler.jp", IDN.toASCII("xn--3-pfuzbe6htf.juggler.jp",IDN.ALLOW_UNASSIGNED))
+		assertEquals("マストドン3.juggler.jp", IDN.toUnicode("マストドン3.juggler.jp",IDN.ALLOW_UNASSIGNED))
+		
+		// 複数のpunycode
+		assertEquals("թութ.հայ", IDN.toUnicode("xn--69aa8bzb.xn--y9a3aq",IDN.ALLOW_UNASSIGNED))
+		
+	}
+}
\ No newline at end of file