I Got a Cheat Skill in Another World and Became Unrivaled in the Real World, Too, Vol. 6 (manga) — Miku

The princess, and the assassin who tried to kill her are not only friends, but rivals for Yuuya’s Love...?! After Luna’s thwarted assassination attempt, she and the princess put the past behind them. And while Yuuya’s thrilled Luna is no longer out to kill Princess Alexia, how the heck is he going to explain his new friend was responsible for the attack in the Weald?! As if fending off the suspicious eyes of nobility wasn’t hard enough—Yuuya will now have to survive a newfound onslaught of affection from his two eager companions.