YUURAKU 有楽 is the Sakai-made professional knife model, from KISHI Cutlery, who makes incredibly high performance knives out of Sakai, Osaka Japan. Their knives are famous for thin blade and superb geometry. The blade has a slight convexity making the cutting feel very enjoyable.
Yasuki White Steel #2(Shirogami or Shiroko in Japanese) is rated at 61-62 HRC. It takes an incredible sharp edge, shapens very easily and also has great wear resistance.