The Hankyu -- Japanese Short Bow

Short bows would be used for closer targets, and might be used instead of shuriken, to ensure a quick kill. Also, a bow could be used to fire a grappling hook up to a ledge that is to high to reach normally. All in all,the Hankyu is probably the only Ninja tool, where the options that the weapons provide, aren't already common knowledge.

http://students.mnmsa.org/~nfredregill/Ninja%20Weapons%20page.html