[!] fix for 101-0502 error on splatoon!

So, just now I was trying to connect to Splatoon, with no avail. I decided to reset the WaraWara plaza, but I also turned off connecting to the Pretendo network. I then restarted my Wii U, and opened Splatoon again. To my suprise; the news worked! (EDIT: Tried it again; still works!) And everything in between works as well!
If you wanna play Splatoon, just do what I did!!!

Thanks for the tip. Unfortunately, though, tricks that work for some people might not work for everyone.