The Gallbladder is the one organ Chinese medicine files in two places at once, and the classification problem is a real one within the tradition rather than an artefact of translation. It is counted among the six fu, the hollow yang organs, which are defined by transmitting rather than storing; and it is counted among the curious organs, alongside the brain, marrow, bones, vessels and uterus, which store rather than transmit. It stores bile, so both are true of it.
It is paired with the Liver in the Wood phase and shares the correspondences of that phase: spring, anger, the eyes, the sinews and the east.
What the classics assign to it as a function has nothing to do with digestion. The Gallbladder is the official of decision and judgement, and courage, resolve and the ability to commit to a chosen course are attributed to its condition. The Liver plans and the Gallbladder decides, and the two are treated as one faculty split across a yin and a yang organ. The association is old enough to have entered ordinary Chinese, where the word for gallbladder does the work of nerve or daring.
The atlas records the western planetary rulership of the gall bladder by Mars, and its humoral association with choler, in a separate article. The two schemes are independent and are not merged here.