Since 1650, Yoshimitsu Hamono has been hand forging blades out of their shop in Shimabara City. They use the highly regarded Aogomi Super steel to make their knives which contributes to amazing edge retention. These knives are pretty average in terms of their thickness at the spine but are ground very thin behind the edge which makes for a great cutting feel. Less space between the choil and handle than most knives we've seen but the impeccable balance makes for an extremely comfortable feel in the hand.
Petty knives are great for all the little things: Chopping shallots and garlic, mincing herbs and butchering small proteins. They function perfectly as a line knife as well as they're nimble, don't take up much space but can still accomplish a wide variety of tasks.