Complete "Attack Of The Kut-Ku", a four star quest at the guild. Once you complete it, you might get an item called Small Kut-Ku Ear. Sell everything from the Kut-Ku except the ear and start a gathering quest at the guild in the forest and hills. Go directly to Area 7 and find the short bald man. He will trade the Small Kut-Ku Ear for a Monster Bone+. You can trade three times. A second, but more annoying way to get it is to take "The Storm Of Yian Kut-Ku" quest at the guild. It is also a four star quest. Kill at least ten and you should get six Monster Bone+s.