Our Last Crusade or the Rise of a New World, Vol. 6 (Manga)

Iska defeats the robot adversaries gunning for Sisbell's life, only to find an indignant Alice waiting for him. Suspicious of each other's motives, the two sisters quarrel over Iska, and he flees amid the commotion. But Sisbell's business with him is not yet finished, and soon, he'll find himself getting more and more involved with her while Alice's jealousy continues to grow...