Story
I. Past
Kira was born to a Fontainian Columnist and a Snezhnayan Adventurer, and had always been fond and proud of her family. As with most families with Snezhnaya, she considers love and family as the most important things, and had subconsciously ignored the warning signs while growing up.
Separation
Since young, Kira had always admired her family, often puffing her chest out in pride every time she would hear people compliment her parents' love and care for one another. Unfortunately, when she turned ten, her family was covered in a veil of shame when the truth about her father was revealed. Not only was he a criminal in hiding, but he was still legally married to someone else. His pursuit for Kira's mother was so that he could comfortably hide within Snezhnaya, and never once being out of love as it was originally painted. Due to this, Kira's parents separated in a horrible manner.
Kira later found out, though, that the reason behind the exposure of her father's identity was because he and her mother went to Fontaine for a quick trip to the Fountain of Lucine prior to her birth. This made people investigate his current identity and state, finding the right time to expose him.
II. New Life
She was originally left under her mother's care, who became the shell of who she used to be. Her distraught state would continuously drill the idea that love is unreliable into Kira's mind, saying it was to prevent her from falling down the same pit as she did; however, it only manifested insecurities in Kira, which would continue to haunt her in the future. In the end, unable to look after Kira anymore, Kira's mother abandoned her in the middle of nowhere. Kira later found out that her mother chose to die out of misery and shame.
"Kira"
On the verge of freezing to death, Kira was then found by a young lady named Mila. Mila originally took her in out of pity, simply wanting her to warm up and survive. After realizing that Kira was alone, though, Mila eventually formally takes her in and gives her the name Kira. For the next few years of Kira's life, she was raised and cared for by Mila, whom she would view as her home and sanctuary.
III. Tianliu Clan
A couple of years prior to the events of the game, Kira came home to Mila's corpse, causing her to grow devastated. She ran around trying to look for clues, and eventually landed herself in a minor intelligence network. It was there that she received clues that her sister's killer is potentially the former Director of the Mercenary Faction, which prompted her to try honeytrapping the current Director, Zivon, to get more information. Although Zivon knew her goals from the start, he played along with Kira until the truth was finally revealed. Kira tried to attack Liu Zhixin after finding out the truth and almost died if it weren't for He Jianyu's intervention. It was then Kira met Xue, the true Head of the Tianliu Clan, and swore her loyalty to her. She then spent the next few years collecting information and working for Xue, all the while cultivating her friendship with, and feelings for, Zivon.
Eyes of the Tianliu
After Xue dealt with Liu Zhixin and reclaimed her position as the Clan Head, Kira kept her alliance towards the clan as well. Not only does she serve as Xue's right-hand man and assistant, but also one of the Clan's Elites and the leader of the Investigation Unit.