Well of Awakenings

The , otherwise referred to as the Kami-sama's Well, was an ancient nexus of Chiryoku located within the Sanctuary of the Guardians in Tougenkyou. It was first verbally mentioned in Calm Before the Storm.

Background
According to The Five Maidens, the was the oldest and strongest focal point of Chiryoku in Tougenkyou. The pool was allegedly the heart of Tougenkyou, and one of Kami-sama's sources of power brought into the physical realm. Popular to contrary belief that Kami-sama brought the Kenmeiotome and the Tenshi into existence with a mere thought, the was also the actual birthplace of the first and second-generation Kenmeiotome and Tenshi.

It was Tougenkyou's most guarded secret, as it was found in the innermost sanctum of the Sanctuary of the Guardians, just beyond the room of Yuu Hoshiko's former Crystal Tomb. Yuu Hoshiko revealed to Mariko Kori and Itazura Kori that the possessed the ability to grant chosen individuals the power to use Chiryoku after they had bathed within the pool. However the process was a double-edged sword since the Well could potentially consume the individual and erase them from existence if their bodies resisted the transformation.

Kiyoko Takara and Ayane Emiko later revealed that the primarily acted as the afterlife for the Kenmeiotome and the Tenshi, where the souls of all the deceased go to after dying. However, this does not apply to Fallen Kenmeiotome and Datenshi because they denied the benevolence of Kami-sama in the pursuit of power. Instead, the souls of the Fallen Kenmeiotome and Datenshi were sent to the Halls of the Reaper, where their souls will be subsequently judged and destroyed for their transgressions. Since the was an extension of Kami-sama's body, it served as the beginning and end for all of Kami-sama's children. It was because of these facts that the was only known to The Five Maidens and the now deceased Twin Tenshi Deities, Michael and Lucifer.

Involvement
One of the decrees Kami-sama had given to The Five Maidens was to ensure the protection of the. Under no circumstances in times of war, should the door to the be opened. Due to the relative importance of the, Yuu Hoshiko and Kiyoko Takara formed the Tougenkyou Guardians for additional protection, whose duties would later expand to the entirety of Tougenkyou.

Sometime after the Tougenkyou War, Inbouka Magatta, the Grandmaster of the Tougenkyou Guardians became curious of what lay beyond the Last Door found within the Sanctuary of the Guardians. Ignoring the edicts laid out by Yuu Hoshiko, Inbouka peeked through the Last Door. However, his act of curiosity and defiance opened the way for a fragment of Lucifer's lingering spirit to make its way into Inbouka's heart. Through the fragmented memories of Lucifer's spirit, Inbouka learned of what truly was beyond the Last Door, which was the existence of the.

Consequently, Inbouka began to desire it. Lucifer's spirit eventually began to envelop the entirety of Inbouka's soul, causing him to become corrupt, spiteful, and a shadow of his former self. Lucifer's spirit would eventually convince Inbouka to enact the Great Guardian Purge, stating that it would allow him to access the without much resistance. Before Inbouka got past through the Last Door, Yuu Hoshiko managed to stop and kill Inbouka, dispelling Lucifer's spirit in the process. However, Yuu's actions were not without sacrifice and she herself was sealed within a Crystal Tomb, which coincidentally barred access to the Last Door.

After the events of the Collapse, Yuu Hoshiko would awaken and shatter the Crystal Tomb, opening up access to the Last Door once again. With the entrance to the accessible once again, a tired and weary Kami-sama went through the Last Door and swam in the. Kami-sama would eventually sink into the bottom of the Well, entering a deep sleep that the remaining members of The Five Maidens worry she may never wake up from.

Yuu identified the as one of the "keys" to Kami-sama's power, the others being the Serenity Jewel owned by the Yume Clan and Tougenkyou itself.

Trivia

 * Since the was a part of Kami-sama, it can be said that Kami-sama herself contains the souls of past Kenmeiotome and Tenshi.
 * The only outsiders who ever had the chance to gaze upon the were Inbouka Magatta, Itazura Kori, and Mariko Kori.