This is due to the fact that the main hall of Dazaifu-tenmangu Shrine has been built on Michizane's burial place (this is particularly unique case while Shinto shrines usually enshrine only the deity's soul).
これは、太宰府の本殿が道真の墓の上に建立されたことによる（通常神社は魂のみを祭るだけに珍しい）。