Kimi wa Kono Mob wo Dou Sabaku no Darou Ka?

is a Japanese light novel series written by Shuichi Nimaru, with illustrations by champi. The series began publication on December 10, 2022 by ASCII Media Works under their Dengeki Bunko publishing imprint.

Synopsis
'''Takuma's sister was killed by her best friend Seiji. The two reincarnated in another world and met again.''' Seiji Takashiro, a perfect high school student who has had murderous impulses since childhood and is the best in everything he does in his studies and sports. Takuma Suganuma, who is recognized as a rival for the first time, appears in front of him, who is incompatible with everyone. The two deepen their friendship, but one day Seiji is questioned by Takuma that he killed his sister who committed suicide. At that moment, Seiji found himself sucked into a magic circle and reincarnated in another world. In the Kingdom of Instreal, where he was summoned by magic, Seiji rises up as the right-hand man of the first prince Durel. On the other hand, Takuma, who was reincarnated like Seiji, has gained the trust of the second prince Ashley as a soldier and has achieved success. After reuniting in another world, the two become embroiled in a battle for the throne between the princes who control the country, and approach the truth behind Takuma's sister's death...