Utakata uses a bubble pipe to create his highly versatile bubbles, which can be used to perform various techniques.
It was shown that this line of ninjutsu allows Utakata to create bubbles with an explosive composition that he can manipulate to attack the enemy. These bubbles can either burst on their own or on Utakata's command.
This technique is expanded on, it is shown to be extremely versatile: Utakata can float inside his bubbles for transport, as well as use them offensively by trapping his enemies in them and filling the bubbles with water to drown them. These bubbles can also be filled with different materials, such as blinding powder, smoke, acid or sticky slime. It was also shown that Utakata's master carried a bubble blower with him as well, hinting that he also used this form of ninjutsu.
In video games, Saiken is able to generate the same type of bubbles from its mouth.