Nope, similar to KH sounds hard... oh wait the final fantasy games! (Obvious sarcasm) Jokes aside, you want a 3rd person view hack n' slash offline arpg huh? If it was just ARPG I'd say diablo 2... but similar to KH for pc... I need to think for a while...
In terms of combat mechanics? The action RPG click to swing sword kind of deal? In terms of astethic? The Disney arts style of look? In terms of story? (Edit: I mean the story progression... semi-linear world after world kind of deal) If you want everything kind of similar to KH... just play KH on an emulator. but yeah, would help if we'd know what you like about KH and want to see in the game you want to play.
Naming an RPG for PC is easy. Naming an RPG like "Kingdom Hearts" for PC isn't. To be blunt, there isn't any that comes to mind with the same style of gameplay or plot.
If we include emulators and atlus games wouldn't raidou be a better option for the arpg feel? And calling on ps1 emulator for Persona 2, and a certain arpg similar to kh called threads of fate Also psp emulator and you can play KH birth by sleep, phantasy star portable 1&2, monster hunter...
I only played the first one and it's been years. If I'm remembering it right I guess it's more of a hack and slash story. Kind of like Bastion? Short but good.
It is an rpg, action rpg tho... Persona is nothing like KH gameplay or story wise tho... tales games are ARPG so they pass that... and the story is good...