Plant biomass is a sustainable resource created by absorbing and fixing carbon dioxide from the atmosphere. The basic unit of cells is made up of nanofibers: cellulose nanofibers (CNF), which are extended polymer chain crystals with a width of 3–4 nm, one-fifth the weight of steel, and more than five times the strength [1]. Half weight of wood and bamboo are CNF by dry weight. Japan’s efforts regarding CNF are the most active and advanced in the world. In Japan, where 70% of the land is covered by forests, the development and practical application of CNF materials for a wide range of uses, such as structural materials for automobiles and electronic devices, building materials, medical, food, cosmetics, etc., are progressing in tandem with basic research [2, 3].