The KI takes Masamoto's Hongasumi yanagiba, long a favourite among Japanese chefs, and rebuilds it in White 1 (Shirogami) rather than White 2. White 1 carries more carbon, so it is harder and purer than White 2, and the knife feels even sharper in hand. The rest stays traditional: hon-gasumi (本霞) single bevel construction with a soft iron cladding and kasumi (霞) finish, wa ho wood handle with buffalo horn ferrule, and each knife shipped with a saya.

The whetstone manners of White 1 are correspondingly demanding: it wants good sharpening technique and a dry resting place more than the White 2 lines do. The line is one knife done very well: the yanagiba in 270, 300 and 330 mm, aimed at the sashimi station rather than the whole kitchen.