The Kamon are Japanese crests. Kamon specifically denotes a family crest whereas mon refers to any crest. For example, The chrysanthemum (KIKU) is the coat of arms for the Japanese Emperor,(this is different from the one is the Japanese passport, although this is a common misconception among many Japanese) . The Mistuba aoi is the Tokugawa family's kamon. Here is a good explanation about kamon. Basically samurai used these crests as family identification as well as on their battle armors. But after Japan's most stable and peaceful period EDO, merchants and artisans began to put crests on items for business too. So there are around 300-400 basic designs and at least 7000-8000 crests. Since most Japanese hardly ever wear a Kimono in our daily life, it is very hard to know and learn about kamon. Actually many Japanese do not know their family creast now. However their desiigns are nice and beautiful, I think. And I heard because of a Japanese design trend, Kamon T-shirt have been selling well. Ah I found a funny i-pod too. This came from a famous historical drama;MITOKOMON.(tokugawa family member). Many western crests have the motif of a fierce animal to symbolize the power of the family. Many Japanese crests were designed based on nature and tools of life. When they used animal designs, they were pigeion, sparrowss, rabbits, or crabs or other such small animals.
Okay let me introduce some good Japanese crests. This site has free dictionary of Kamon data, you may check their huge sample. please click left side letter link. I picked some.
Nature --- moon, star, wave, snow.
Plants ---cherry, plum, pine, bamboo, rice.
Animal ---chidori, butterfly, crane, rabbit.
tool & design ---wheel, fan, Japanese fan, bell, hat,
I suppose you know Kikkoman which is a famous soya sauce maker, their logo is a crest called Kikko. Kikko is the motif of a tortoiseshell. I want to introduce more, but it is impossible, there are so many crests! I think you may find your favorite design there. Please try it! By the way my family crest is this Yokomokko, I am not sure, maybe so.