The hitoyogiri (一節切) stands as one of the most fascinating direct ancestors of the modern shakuhachi. 

Like the latter, it features five holes—four on the front and one on the back for the thumb—and a mouthpiece defined by a diagonal cut that acts as a blowing bevel. This instrument reached its zenith and popularity during the Edo period (1603–1868), before giving way in the 19th century to the contemporary morphology of the shakuhachi, characterized by a more robust body and the integral use of the root.

The study of its historical morphology reveals a notable flexibility in its proportions, conditioned by metrological and botanical factors:

• Variation in units of measurement: The value of the shaku in pre-modern Japan was neither universal nor strict. Depending on the period and the workshop, the standard fluctuated, allowing some instruments to lean toward proportions of 1.1 or 1.2 shaku.
• Natural availability of bamboo: Traditionally constructed from a single segment delimited by an upper node (hito-yo-giri literally means "cut by one node"), the artisan was subject to the physical dimensions of the plant. Finding a stalk with a greater distance between nodes made it possible to create tubes of expanded dimensions.
• Acoustic criterion: A 37 cm tube—close to 1.2 shaku—provided a subtly lower and deeper register compared to the ultra-compact 33 cm formats, a preferred timbral choice in certain musical and literary circles (bunjin).
  

While the general trend of the era pointed toward more compact formats, the analysis of international museum collections—such as the specimens housed in The Metropolitan Museum of Art—confirms that the length of the hitoyogiri varied according to the luthier's criterion and the morphology of the bamboo.