Miki

Miki is one of the main characters of the main plot "Lifestream" and the Elder Spirit of Life Energy.

Backstory
Not much is known about Miki as of now. All that is known is that she is one of the strongest Elder Spirits in the Spiritual World Council, representing the affinity "Life Energy." She also narrates the "Prologue" chapter in "Lifestream: Endowment of a Spirit."

Lifestream Endowment of a Spirit
Monitoring Kaika Miki does not have a direct appearance or confrontation with Kaika  when she runs into a Shadow Replica twice during the final school day, but she does keep an eye with her. Seeing that there were already Shadow Replicas taking place in the Living World to hunt down Kaika before the pact is made, Miki decides that she will have to rush the process and create the pact alongside Kaika.

Awakening The Pact
When Kaika reawakened in her subconscious, Miki finally confronts her, and tries to bring hope towards her. While Kaika tries to refuse any of what she says, Miki reveals that they were in her subconscious and not the afterlife, and also tells her that she survived the car crash earlier due to Miki preventing that fate with a faint miracle strand. She also explains to Kaika about the spiritual pact, and that this is the fate that Kaika has to take. To further prove her point, Miki creates a vision of Kaika and Kuro safe in a barrier from the Shadow Replicas. Seeing that there was no lie to this, Kaika accepts the pact with Miki, and Miki sends Kaika back out of the subconscious so she could awaken at the scene.

Miki reappears to tell Kaika to "focus" and everything will fall to place, knowing that it would trigger Kaika's pact into motion. Kaika does so, and it all activates in a nick of time. While Kaika fought against the Shadow Replicas recklessly, Miki protects Kuro for Kaika. As the Shadow Replicas were gone, Miki disappears from sight before Kaika could ask more from her about everything she doesn't know.

Settling With The Truth
During Kaika's drive towards the orphanage, Miki reappears and tells Kaika not to talk to her vocally, as she could just talk to her through her thoughts. Kaika then mentally asked her about who the enemy is if she has the pact. Miki then explains to her about the Living World, Spiritual World, After World/Alternate Side, and the war that took place years back. She also explains the importance that Kaika has as a Pact Bearer of the most important affinity. Once the car arrives at the orphanage, Miki disappears from sight.

The spirit makes another appearance as Kaika is alone at her new shared room with Luki, and mentions that Kaika would need training if she were to be any fluent within her pact. Kaika agrees, and says that she'll rest up for the night. Miki disappears, thinking that Kaika was asleep the entire time while she sneaks out to date with Sota. Miki returns as Kaika demands her appearance, and asks why she didn't appear during the Shadow Replica horde in the downtown area. Miki replies that she thought she was asleep in the first place, and that the Shadow Replicas were handled by another Pact Bearer. Kaika then says she will sleep for real this time, and Miki only disappears.

Appearance
Miki has the body structure of a pre-teen girl. She wears a pure white kimono that has lacing and a small white ribbon around the neck, a white corset around her waist, and she wears white shoes. Her blonde hair is tied with two ponytails, the left ponytail shorter than the right ponytail, which is tied with a magenta butterfly pin. She is often seeing floating, never setting foot on the ground.

Elder Spirit of Life Energy
Miki is known to be one of the strongest Elder Spirits because of her affinity, Life Energy. Being an Elder Spirit, she is enabled to manipulate an affinity within the Living World to an extent, which in this case is the world's Life Energy. Also, she can share her power of Life Energy to a Living who has a high amount of Soul Energy, and give them a Spiritual Pact of Life Energy. Like all spirits, Miki is able to shift between Living World Realities to Spiritual World Reality.

Personality
Miki is portrayed as an emotionless and knowledgeable character, who only has her own decisions for the better of the realities. She only helped Kaika survive the car crash because Kaika was the only possible person to hold the Spiritual Pact of Life Energy. She also tells Kaika to train herself, knowing that Kaika's new fate was going to catch her soon. Miki only says what would guide Kaika into using her newfound fate to affect the realities positively. All of this makes Miki appear as a selfless and obedient spirit for endless peace. She also shows no rashness towards those tied with the Shadow Replicas, only going by on what would be a path to a new peaceful fate.