About the shape - Santoku means 'Three Virtues' or 'To solve Three Problems'. The three virtues are meat, fish and vegetables, or slicing, dicing and mincing depending on your interpretation. This means that the Santoku is an all-around knife, suitable for the amateur home cook and the professional chef alike. The heigh means good clearance for big hands, while the relatively short blade can be wielded by anyone.
About Hinokuni Sakai - Yukihiro Sakai-san was apprenticed under Nishida-san in Kumamoto, who strictly forge-weld steels in house. Sakai-san has learnt everything from Nishida-san and continues to do like his sensen. Sakai-san recently started his own workshop in Kumamoto making his own knives.
Now he forge-welds everything in house, from hard carbon steel clad with soft steel. The Shirogami #1 steel used in these knives is forge-welded in house by Sakai-san. This is a very traditional steel that can achieve incredible sharpness and has great edge retention, a favourite of more traditional blacksmiths.
Hinokuni is a nickname for Kumamoto Prefecture, meaning a Country of Flame, because of the famous volcano Mt. Aso.