Mitou Shoukan://Blood Sign

Mitou Shoukan://Blood Sign (未踏召喚://ブラッドサイン, lit., "Unexplored Summon://Blood Sign") is a complete light novel series written by Kazuma Kamachi and illustrated by Waki Ikawa under the Dengeki Bunko imprint. The first volume was released on September 10, 2014. The series is currently complete at 10 volumes.

Synopsis
Summoning Ceremonies can freely call forth even "those which lurk in the depths beyond the gods". One boy has top-level abilities even among the cutting-edge summoners who can use those ceremonies.

He is Alice (with) Rabbit aka Kyousuke Shiroyama.

But this strongest summoner has a single fatal weakness.

A certain "cursed words" spoken by girls: "Help me."

When Kyousuke hears those words from Higan Meinokawa, a girl brought to the verge of death, he throws himself into a city where three great summoner forces clash!

Characters

 * Kyousuke Shiroyama (城山恭介) - The story's main character. He is a Summoner, affiliated to one of the Three Great Summoner Powers called "Freedom". He is given Award #902 for his remarkable talent, but he constantly suffers from his uncontrollable urge to assist those who ask for help. He is currently in high school, and is considering to retire from being a Summoner.
 * Higan Meinokawa (冥乃河彼岸) - A vessel affiliated to one of the Three Great Summoner Powers, "Freedom". She is the younger sister of Renge Meinokawa.
 * Renge Meinokawa (冥乃河蓮華) - A Summoner who belongs to "Freedom". Her vessel is her younger sister Higan, whom she treasures above all else.
 * Lu Niang-Lan (緑娘藍, Ryu Nyan-Ran) - A vessel who belongs to one of the Three Great Summoner Powers, "Illegal". She known by those who fear her as "Soushin Anki" (lit., "weapon concealed in a slim figure"), who can slaughter even experienced Summoners by using weapons hidden in her flesh. She is also a second-hand goods seller.
 * Aika (愛歌) -  A Summoner belongs to one of the Three Great Summoner Powers, "Government". She is a shut in who idolizes Kyousuke, affectionately calling him "Onii-chan". She has a pet white liger which she uses as her vessel.
 * The White Queen (『白き女王』, Shiroki Jo'ou) - A top-notch Material among those called forth by Summoners. She is said to lurk "beyond the realm of the gods".
 * Azalea Magentarain (アザリア＝マゼンタレイン, Azaria Mazentarein) - An affiliate of "Government" who shows hostility against Kyousuke. She is a brilliant Summoner, also called as "Golden Luxury".