I read/write a lot of fanfiction, some of it in the anime department. As such, I have a fair grasp of 'fangirl Japanese' and even understand the honorifcs system. Yay me! However, I'm about to start a project from Sakura's point of view and have noticed a trend in the fandom in a slight difference in how they refer to each other.
Sakura seems to always refer to Tsunade, as Tsunade-shishou, while others call her Tsunade-sama, or in Naruto's case, something along the lines of obaasan.
Now, wanting to be correct in my use of honorifics, I googled both shishou and japanese honorifics, thinking that -shishou might be a higher form of sensei or something of the ilk. I found out that it wasn't listed on any of the honorifics lists or tutorials I looked at, and according to Wikipeda is a city in China.
I also looked up Tsunade-shishou and found a number of fan sites.
My question is this term correct, and if so what does it mean? Would substituting -sama be just as correct?
Thank you in advance :)