Which ukiyo-e artist is known for his 'Manga' sketchbooks?

The ukiyo-e artist known for the Manga sketchbooks was Katsushika Hokusai.

The Hokusai Manga is a large collection of sketches covering landscapes, people, animals, plants, everyday activities, and supernatural beings. Despite its name, it is not a modern-style comic: the drawings are not connected by a continuous story. In Hokusai’s time, manga could mean informal or spontaneous drawings.

The first volume appeared in 1814, when Hokusai was 55. The work was initially conceived partly as an art instruction book and became popular enough to lead to additional volumes. Thousands of images were eventually arranged across fifteen volumes, with later volumes published over several decades and some issued posthumously.

Hokusai’s sketchbooks helped spread his observational style in Japan and later influenced Western artists and audiences. The title should therefore not be confused with the general category ukiyo-e, or with the work of Kuniyoshi, Hiroshige, or Utamaro, each of whom had a different artistic specialty.