Yagura Hatake (矢倉はたけ, Hatake Yagura), who simply introduced himself as Grandfather (おじいさん, Ojiisan) before Minamoto "Hikaru" Kazuhira revealed his actual name, is an old and experienced pirate, and the first-mate on-board The Serenity. He acts as Koga Hayashi's mentor, and is the actual grandfather of Kenshiro Hatake.