Himitsu – Kuro no Chikai
Author: Hitoshizuku-P
Latest: Epilogue
Summary:
Based on the popular Vocaloid song Rin, a young angel (presuenders) falls in love with a young huirl, Miku However, their love is considered taboo, and so, Rin makes a deal with the devil to be reborn as the human boy, Len, in order to be with Miku However, their happiness together is short-lived, and even that soon ends in tragedy