Responses
After rereading it again, I'm still wondering how was she his zanpakuto and a lieutenant at the same damn time?! But then after getting to this point: http://www.mangago.zone/read-manga/bleach/mr/manga/bleach/vTBD/c670/pg-14/
I thought maybe he's SO powerful, that Yachiru was able to manifest herself as shinigami and nobody noticed??????
So Yuchiro really was kenpachis Zanpakuto???