Writing threads with myself for plot??

Hullo there... 

I saw a question in here about writing with one's self for trades (not allowed, understandably). I wanted to know if we could write with ourselves just for plot purposes? Self-fulfilling plot purposes? It would only be to develop character, you see. 

Apologies if this has already got an answer somewhere. I tried doing a little search (didn't try awfully hard though aha).

It's absolutely fine to write threads with yourself for plot purposes!

It's absolutely fine to write threads with yourself for plot purposes!

Thank you! Cheers!