Abunai

The Abunai (阿文愛, Abunai) is the second Yakikage's sacred infamous weapon. A massive boomerang that actually towers well above her, Chosho's older brother and previous Yakikage had an old weapons smith create it before passing a unique trait upon Abunai. It became her signature. Something that entire countries know her for. She developed complex fighting styles and techniques around it....

Although heavy for most men, Chosho describes Abunai as light as a regular boomerang...

The Abunai is capable of locking down on a targets chakra and following them...Her chakra causes it to always return, no matter how far. Even if knocked down, it will continuously return back to her will...