which one should i play? kai or without kai?
Same question, have you figured it out?
There are 3 Rance02 version:
Rance 02 - regular version, has updated art but stays to true original game both in terms of lore and gameplay, having almost 0 edits. If you want to see how game originally looked then you want this. Not worth it if you only want to play one tme.
Available on english.
Rance 02 Kai - 'game revisioned' patch(in our case preinstalled version of the game) to include all changes they wanted to make to suit the lore all the way up to Rance X as those changed a few things as games went along.
This is a HEAVY edit of the game AND moderate edit to the gameplay.
This is the recommended version to play for english speakers who want to experience entirety of Rance(excluding Kichikuou which is essentially a very old version of what would Rance X look like)
English version of 'Kai' patch aka mangagamer aka patch you have in this thread has some changes from KaiKai patch as well.
Rance 02 KaiKai - 'final patch' includes a few more lore changes and quite a few gameplay balance tweaks. It's more of a gameplay patch basically, so don't worry too much that you skip it if you are in it for lore. It does cover a few details you wouldn't know until later but nothing important you really need to know.
In terms of gameplay it's a pretty heavy rebalance of things as well as adding quite a few extra secret loot to some previously useless places.
This is the recommended patch but it's only for those who can speak Japanese since this patch has no translation.
TLDR:
As english speaker - play Rance 02 Kai and move on.