Yureka is a AI created by a hacking software, and accompanies Lotto in Lost Saga. Her real-life counterpart is Jaeha, a would-be killer, and she represents a part of Jaeha's personality. Yureka has deep love for Lotto.
Jaeha
The maker of Yureka. Originally a hunter, she partners up with Elca, and hopes to become a killer for the sake of avenging her parents who committed suicide after being pushed into a corner. She also loves Lotto.