Hirano-ku (平野区) is one of 24 wards which make up the city of Osaka, and is located in the southeast of the city. It is the largest Osaka ward in population and the only ward to have over 200,000 residents.
The north-west side of Hirano-ku is on the southern part of the Uemachi Plateau, but the overall terrain is mostly flat. The Yamato River flows through the south of the ward, and the Uriwari Cemetery is located inside the ward.
The name Hirano probably goes back to the end of the Heian period, and was formally known as Hirano-shou in Sumiyoshi-gun (district) of the Settsu province. The second son of Sakanoue no Tamuramaro, Sakanoue no Hirono, was the feudal lord in charge of the development of Hirano and was called Hirano-tono (tono being the title given to noblemen).
There are a couple of theories as to the origin of the name Hirano. One is that it is a corruption or mispronunciation of the word kouya (広野). Another theory is that it comes from the time when many lakes and marshes were reclaimed and the fields (野) were widened (平らになった) making the kanji combination 平野.