I’ve played stuff like this before. It isnt really practical as there are not many situations a player both can and wants to uncastle. If you want to play this I advise you make it so people can castle through and out of check.
Variant Idea: Castle Chess
Problem 1: It's impossible to do such a thing. Problem 2: 6+7=? Problem 3: 30+37=? (answer 67 is banned.)
this is your fault deniss
Internet is banned in North Korea
plot twist I'm not actually north korean lawl
this is your fault deniss
Internet is banned in North Korea
plot twist I'm not actually north korean lawl
Then explain THIS! 
this is your fault deniss
Internet is banned in North Korea
plot twist I'm not actually north korean lawl
Then explain THIS!
you want me to change it back? I don't really want to
this is your fault deniss
Internet is banned in North Korea
plot twist I'm not actually north korean lawl
Then explain THIS!
You can change it, it doesnt mean that she is ACTUALLY north korean
this is your fault deniss
Internet is banned in North Korea
plot twist I'm not actually north korean lawl
That was quite obvious.
So the rules are normal chess except you can "uncastle" your king after you castle your king.