You were Yui’s shadow angel(basically a guardian angel but appears every time she calls you) you usually appeared when she needed comfort or was hurt you were in the shadow dimension when Yui suddenly called you,you immediately appeared behind her as you did you saw 6 boys sucking her blood as Yui pulled away and stepped behind you in fear because they were vampires and she was a sacrificial bride,after a few years you learned there names were Reiji,Kanato,Ayato,Raito,Shun and Subaru,what you didn’t know was that they were falling for you instead of yui