Tojiro offers excellent quality knives, handmade using traditional techniques with levels of sharpness and durability aimed at professional kitchen use.
The values instilled in Tojiro's production, coupled with the value for money make them a no brainer. A very full range of excellent knives should offer you everything you need.
This range is made using a VG10 core steel with a lighter cobalt coating. This means the blade retains most of the statistics of VG-10 with a HRC rating of ~60 while the softer stainless steel coating helps to make sharpening easier.
This makes it a very strong knife for it's excellent price range.
Petty knives are a smaller blade mainly used for slicing or chopping veg, meat, herbs, or perhaps even filleting a fish. A vital knife for when a Gyuto (all-purpose chef's knife) is too big. Blades are the same profile as a Gyuto, but are normally between 120mm and 150mm, with the smaller blades being used for peeling or removing ends off the chopping board.