Bleach: Harbinger/Extinction

is an arc in Bleach: Extinction that takes place seven months before the events of Phantom Ascent, and is primarily concerned with the who are members of the organization Xstence, although other organizations and races are involved.

Introduction
Xstence was formed with one goal in mind: the protection of fellow humans, from both themselves and Hollows. For this reason, members train diligently in order to master their powers, relying on each other for wisdom and guidance. They are autonomous and secretive, looking out for their own interests and shunning outsiders. Currently, their active goal is to seek out Fullbringers who have received soul fragments. Although these fragments were dispersed nine years ago, the powers associated with them are just starting to emerge. It is important that the Fullbringers learn to use this newfound power effectively, although why they are intent on gathering them and training to use them in the first place remains unknown. Although Xstence seems to be unaware of the true nature of the shards and their inherent connection to, their actions in seeking out these fragments brings them into direct conflict with a mysterious individual who is after an enigmatic dark power. Whatever the case may be, it will be up to the members of Xstence to stop this adversary... and to survive.

Plot
On May 30th a strange rift appears above the skies of. Strange creatures emerge from this rift, and a small fishing barge that was caught in the sudden unleashing of power is sunk, killing all on board. The monsters are believed to be Yōkai, and they make their way towards Osaka. Meanwhile, in Ikeda, the members of Xstence notice the rift and the monsters. Tetsuo Momohara calls a meeting to order at the organization’s headquarters, and from there they pair up and head out to investigate and engage the strange creatures.

Sidestories
List all sidestories pertaining the characters that appear in Harbinger here.

Protagonists
Xstence: (In order of appearance)
 * Michiyo Tanaka
 * Kōhaku Morimoto
 * Kalyn
 * Ran Kobayashi
 * Juro Kageyama
 * Amaka Yoshida
 * Saki
 * Tetsuo Momohara
 * Emi Tenka
 * Otoya Kurogane

Minor: (In order of appearance)
 * Kabuto: a navigator who was killed when his ship was attacked by Yōkai.
 * Kamiki: a guard employed at the office building where Kōhaku works.
 * Juro's Parents
 * Amaka's Parents
 * Convenience store clerk: a late night employee who sells to Emi.

Antagonists
Minor: (In order of appearance)
 * Rift Creatures
 * Okami and Partner: two muggers who were defeated by Juro.

Setting

 * Ikeda, Osaka
 * Hōnara
 * Xstence Headquarters
 * Michiyo's Flower Shop

Trivia

 * A harbinger is a person or thing that announces or signals the approach of another.