Casey knows the rules. Don't meddle with life and death, don't give away your identity, don't show any emotions. His kind aren't capable of feeling emotions. But when Casey's given a case where two rules are impossible to follow, how will he hide the fact that he's never been following the third?

When 25 year old Ru decides to end his life in the next twenty two days, a mysterious young man appears before him claiming to be a Soul Collector - and tries everything in his power to keep Ru alive, despite it going against his job.