Reyna's world changes forever when he discovers that his father, the deputy commander of the Star Ocean Rangers, has been assassinated. He is determined to track down the real culprit behind it and seek revenge.
Reiner encounters Cassius for the first time, and their initial conflict and subsequent cooperation. Cassius's ability: Mind manipulation, the ability to influence the decisions and feelings of others, but requires concentration.
While collecting intelligence, Reina and Cassius discovered that the Sun Empire was related to the assassination, and decided to sneak into the empire and start their first investigation.