Board Thread:Questions and Answers/@comment-4310945-20140507170930/@comment-24915654-20140508003826

Her badge and her kosoda were lying on the ground. And looking rather in tack. I saw on another forum a reminder to look at the flash back of Yachiru first meeting with Zaraki that happens in Chapter 577. And that this event occurs after he said his zanapkuto's name. So one could infer that Yachiru was Zaraki's zanpakuto. Maybe that is why she was so fascinated with his blade. She was seeing for the first time how Kenpachi had been treating her.

It may also be Why Yhwach masquerading as Ichigo's zanpakuto was able to notice how Kenpachi could not even hear his zanpakuto during their fight. And why Yachiru stands by watching all his best fights so intently but not getting involved. I hope we will see this confirmed in another flashback to the moment when Kenpachi could finally kill Unohana.