Doro no Bunzai de Watashi dake no Taisetsu wo Ubaou da nante

Protect the girl who is destined to die an untimely death. That is the mission given to me and "Senpai" from the heavenly realm. I can't believe that our job is to come down to earth and protect stupid human beings... and an ordinary girl at that? Why do we, beautiful angels, have to do such a thing! "Senpai" must have been thinking that way all along. That's what I believed, so why...

(Source: Kadokawa, translated)