Nakatsugi-kan is usually made by joining two parts of the bamboo pieces using a different kind of bamboo piece. It is beneficial to have a durable individual in the middle of Shakuhachi as they are often taken apart and put back on together. Gyokusui Tomojin style was born to bring Nakatsugi-kan closer to the original form of bamboo with minimal use of external materials. Making Tomojin Nakatsugi requires a lot of time and precision. This involves carving the inside of Jyokan (top part) to enlarge the inner diameter and shave off the outside of Gekan (bottom part) so that they will fit snugly and create the perfect seal for playability.