Wow, I totally missed the TGS news that Kingdom Come: Deliverance is coming to Japan in Spring 2019. Published by DMM Games for PC and PS4.
https://www.famitsu.com/news/201809/22164632.html
I think this game could do pretty well, around the 100k mark. Here's what similar games did in Japan (MC CY data):
218./043. [PS4] The Witcher 3: Wild Hunt <RPG> (Spike Chunsoft) {2015.05.21} (¥8.200) - 22.819 / 188.591
(-86%) (67.385 <91,97%>)
125./147. [PS4] The Witcher 3: Wild Hunt - Complete Edition <The Witcher 3: Wild Hunt \ The Witcher 3: Wild Hunt - Hearts of Stone \ The Witcher 3: Wild Hunt - Blood and Wine> <RPG> (Spike Chunsoft) {2016.09.01} (¥6.480) - 40.223 / 88.062
(-16%) (11.948 <67,82%>)
Total LTD [PS4] The Witcher 3: Wild Hunt - 276.653
748./144. [PS4] Fallout 4 # <RPG> (Bethesda Softworks) {2015.12.17} (¥7.980) - 1.851 / 228.897
(-96%) (123.018 <72,40%>)
233./000. [PS4] Fallout 4: Game of the Year Edition <Fallout 4 \ Fallout 4: Wasteland Workshop \ Fallout 4: Far Harbor \ Fallout 4: Automatron \ Fallout 4: Contraptions Workshop \ Fallout 4: Vault-Tec Workshop \ Fallout 4: Nuka-World> <RPG> (Bethesda Softworks) {2017.09.28} (¥5.980) - 18.152 / NEW (6.507 <65,51%>)
631./000. [PS4] Fallout 4 [New Price Edition] <RPG> (Bethesda Softworks) {2017.09.28} (¥2.800) - 2.817 / NEW (854 <53,95%>)
Total LTD [PS4] Fallout 4 - 249.866
140./130. [PS4] The Elder Scrolls V: Skyrim - Special Edition <The Elder Scrolls V: Skyrim \ The Elder Scrolls V: Skyrim - Dawnguard \ The Elder Scrolls V: Skyrim - Hearthfire \ The Elder Scrolls V: Skyrim - Dragonborn> <RPG> (Bethesda Softworks) {2016.11.10} (¥5.980) - 32.535 / 86.952
(-40%) (27.330 <35,30%>)
Total LTD [PS4] The Elder Scrolls V: Skyrim - Special Edition - 86.952
018./000. [PS4] Horizon Zero Dawn # <RPG> (Sony Interactive Entertainment) {2017.03.02} (¥6.900) - 228.772 / NEW (116.997 <92,21%>)
229./000. [PS4] Horizon Zero Dawn: Complete Edition <Horizon Zero Dawn \ Horizon Zero Dawn: The Frozen Wilds> <RPG> (Sony Interactive Entertainment) {2017.12.07} (¥5.900) - 18.302 / NEW (7.309 <46,72%>)
Total LTD [PS4] Horizon Zero Dawn - 247.074
052./000. [PS4] Ark: Survival Evolved <ADV> (Spike Chunsoft) {2017.10.26} (¥6.800) - 129.989 / NEW (70.177 <80,87%>)
Total LTD [PS4] Ark: Survival Evolved - 129.989
09./08. [PS4] Conan Exiles <ACT> (Spike Chunsoft) {2018.08.23} (¥6.800) - 8.528 / 68.757
(+12%)
Current LTD [PS4] Conan Exiles - 68.757 and growing
Of course Kingdom Come is closer in terms of budget and scope to Ark and Conan Exiles than The Witcher 3 and Fallout 4, but combining these sales numbers, it shows that there's a pretty big audience for western RPGs on PS4 in Japan, and even for 'lower-budget' (cough) experiences. Games like Far Cry have been growing immensely over the generation as well. This trend, as well as the effort they seem to put into the localisation with full Japanese voice acting and such, makes me very confident that Kingdom Come: Deliverance can become a nice seller for PS4. 100k should be a lock.