Olika själar har olika andliga tryck ( reishi ). Genom träning kan själar förbättra deras användning och kontroll av den kraften (oftast inom Gotei 13). När de får tillräckligt med makt måste de bestämma namnet på deras zanpakuto. Vi ser aldrig någon under officerens rang eller namnge eller släppa sin zanpakuto (räknar inte Ichigo), och detta överensstämmer med "training = release" temaet genom Bleach
A Shinigami can obtain their Zanpakutō by solidifying their Rieryoku into a Sword form. According to tradition, when a Shinigami graduates from the academy they will gain their own unique sword. However the actual process in which this is done has not been shown. What is known about the obtaining of a Zanpakutō was shown through Ichigo Kurosaki. He was trained independently in a perhaps unorthodox manner and gained his Zanpakutō through means of digging deep into his own soul to grab the power he had never had before. Whether this is the method used commonly for Shinigami is also still unknown. When a Shinigami obtains their own Zanpakutō they learn it's name as a way of "activating" it. This activation of power will release the Sword's Shikai, the first released state of any Zanpakutō. When the sword changes into this form, what is actually being seen is not the change of state, but the true form of the Zanpakutō.