Senkaimon

Shinigami come and leave Soul Society by unlocking the. When guided by a Hell Butterfly, the Senkaimon takes the form of a waiting room entered through a sliding door. Humans can also use such a gate through the use of, which convert solid matter into spirit particles. A variant on this gate using four marked points can allow entire towns to be moved into Soul Society, as is done to Karakura Town to prevent Sōsuke Aizen from destroying it.

Intruders can pass through the senkaimon in the same manner. While this method uses the same gate, the lack of a Hell Butterfly forces intruders to pass through the, a bordering dimension between the human world and Soul Society (not to be confused with Hueco Mundo). This is much more dangerous to do, as souls that cannot pass through before the gate to Soul Society closes are trapped there forever. It is possible for Seireitei to deactivate these mechanisms, allowing Shinigamis or humans to traverse the dangai safely. While the Senkaimon are run by the Kidō Corps, during the Shūsuke Amagai arc it is shown that they are private Senkaimo own by rich families.