Luna Ione has been searching for Crime, an organization of fellow ability users, for six years. Despite the organization's questionable methods, she seeks their help in order to find her missing older siblings, Violet and Eon. But while continuing her search, she has a chance encounter with Regret, another organization of ability users. Making a deal with Regret, who seem to have a similar objective of finding Crime, Luna temporarily joins as a new member. But though Luna has joined forces with Regret, she's about to find out that the situation between these two organizations may be more complicated than it first seemed...