Kirabris has lived a decent life on Earth, so far. She was brought up in a somewhat traditional upper-class family, and took in an orphan as her, sister? When they were kids. Life happens, school happens, the "sisters" fall in love, and with their best friend, making the best poly relationship ever, right?
Life is good and dandy for another 6 years, until the voices come. Well, quite literally. A system. A system is extracting the soul of Kirabris for who knows what? She doesn't want to go without her girlfriends though, so they come with. They then wake up in a dungeon, and slowly but surely Kirabris awakens memories of who she used to be, and all the troubles that come with it.
They will live on this planet, for a while. Getting stronger, making connections, meeting "old" friends, and learn how to live in a brutal new life. The goal? Whatever lies beyond godhood.