'Pacifying the soul'= [mi]tama-shizume. A chin-kon-sai (matsuri for the pacification or repose of souls) is held in the imperial palace before the daijosai and the rite is practised especially at the Iso-no-kami jingu, Tenri, Nara. The idea of chinkon derives from the belief that a soul which had departed from the body at death could be brought back by rituals including dancing, in forms resembling early kagura. There are several different interpretations of chinkon or tama-shizume including drawing on the strength of a gai-rai-kon, a (higher) soul from beyond; pacification of one's own soul and of others, including the whole community; a kind of intercession for the souls of the dead; unification of dead souls with the kami, and promotion of the 'soul' of the state and the sovereign.
A Popular Dictionary of Shinto. Brian Bocking.