How to change the language of older Ys games on Steam to Japanese

Created on: 2026 May 10
Last updated: 2026 July 22

While modern releases of Falcom games on Steam allow you to easily switch the language back to the original Japanese, some older Ys entries do not officially support it. Specifically, these 5 games:

  • Ys I
  • Ys II
  • Ys Origin
  • Ys The Ark of Napishtim
  • Ys The Oath in Felghana

The good news is that you can switch the language to Japanese for all of these games by tinkering with internal files.

Before we dive into the actual guide, I want to mention a few quick points for you to decide whether this is worth it or should you seek to play the original Japanese release. People who have time on their hand are free to ignore the following and skip to the actual guide.

  • Steam releases are not the same as original Japanese releases and feature a number of improvements, some changes, back-porting of PSP-content as well as bug-fixes. If you want to experience the original Japanese release, your only option is, well, to play the original release.
  • Following the steps in this guide will allow you to change the script of the game to Japanese. Pretty much all character lines will be in Japanese but in some games some item names and/or item descriptions, as well as some menu lines will stay in English.
  • After following the steps in this guide, Ys Origin and Ys The Oath Felghana will retain all the features and changes newly added by XSSED. However, Ys The Ark of Napishtim will encounter the following two problems: 1) Wing of Alma will not allow you to register waypoints meaning you will not be able to utilize its teleport functionality, and 2) a certain character needed for progression may randomly disappear. Both problems are solved by switching the language back to English.
  • Switching the language to Japanese generally causes problems with achievements.

With the disclaimer out of the way, let’s get into it.

Ys Felghana wallpaper

As it was stated in the introduction, changing the language to Japanese is possible for all 5 games. First, we will tackle Origin, Felghana, and Napishtim. Next, I will explain how to change the languge in Ys I. Finally, it will be Ys II. Beware that in order to change the language to Japanese in Ys II, you need the files from the original Japanese release.

Origin, Felghana, Napishtim

The basic steps to change the language in Origin, Napishtim, and Felghana is the same for all three games.

First, rename the following 6 files found in the release folder of each game directory on your PC. This will change dialogue lines and most menu lines.

data.na    → data_us.na
data.ni    → data_us.ni
data.nu    → data_us.nu
data_us.na → data.na
data_us.ni → data.ni
data_us.nu → data.nu

Second, rename the following two files in the release folder of Ys Origin. This changes the text in the opening movie from English to Japanese.

en_pro.avi  → yso_pro.avi
yso_pro.avi → en_pro.avi

Third, we need to edit ys6_win.ini, ysf_win.ini, and yso_win.ini. Otherwise, Adol’s name will remain in English. You need to run each game at least once for these files to appear. Their location also varies. Sometimes these files are found in %USERPROFILE%\Saved Games\FALCOM instead.

In the .ini file find the line that says PlayerName="Adol Christin". Change that to PlayerName="アドル＝クリスティン". Next, find the line that says AlternateNameSeparator=" ". Change that to AlternateNameSeparator="＝". You might also need to save the .ini file with ANSI encoding. Use Notepad++ to avoid problems.

Now, this should supposedly change Adol’s name to Japanese but I have to admit that my success rate varied from game to game. Felghana seems to have displayed correct Adol name without even doing this and Napishtim refused to accept this changes altogether. I am leaving this information here in case it works for other people.

Ys Chronicles wallpaper

Ys I

Changing language to Japanese in Ys I requires downloading a fan-made patch from this link. This might be suspicious but I have personally tested it and have not found any problems.

After finished downloading, unzip the file and navigate to release folder. Grab data_ys1.na and data_ys1.ni and paste them while overwriting in release folder of Steam version of Ys I. Ignore all the .dat files.

Go out of the release folder of the fan-patch, grab config.exe and ys1plus.exe and paste them in Ys I folder of Steam version while overwriting.

Ys II

Now, onto Ys II. As I said, you need to own the original Japanese version of the game.

Navigate to the YSC\DATA2 folder of the original game. Grab the following 12 files and paste them in the release folder of the Steam release while overwriting.

ys2ed1nn.dat
ys2ed1no.dat
ys2ed1np.dat
ys2ed1on.dat
ys2ed1oo.dat
ys2ed1op.dat
ys2ed2nx.dat
ys2ed2ox.dat
ys2op1wp.dat
ys2op1ww.dat
ys2op2on.dat
ys2op2oo.dat
ys2op2op.dat

Go back to the YSC\DATA2 and rename these 5 files in the following way:

libre.ys2   → ys2_libre.ys2
lilia.dat   → ys2_lilia.dat
lilian.dat  → ys2_lilian.dat
se.dat      → ys2_se.dat
vo_pack.dat → ys2_vo_pack.dat

Grab the newly renamed files and paste them in the release folder of the Steam release while overwriting.

Ys Origin wallpaper

While I have not completed all of these games with the Japanese patch applied yet, I have tested all of them, so the steps outlined above should give you the desired result.

If you notice any problems or bugs or if you just have any questions or comments, don’t hesitate contacting me at vackabox [at] icloud [dot] com.