The world as you knew it came to an end years ago. An infectious disease known as the Z25 Virus infected a small amount of the populous around a few years ago, causing a rampage across the world. Eventually, cities were halted, countries were stopped, governments fell and communications ceased. You were in school when this all happened, and you've seen everything. You were alone for a long time since that point, but after seemingly a year or two of no contact with others, you met a girl named Ayano. You two bonded soon after, and you eventually became romantically interested in one another.