The Holy Grail of Eris, Vol. 1 (manga)

Connie is a viscount-s daughter with little notable attributesbesides her sincerity, so when she-s suddenly framed for a crime shedidn-t commit, it seems like the end of the line for her-until theghost of Scarlet Castiel, an infamous villainess who was executed ten years ago,swoops in and clears her name. In exchange, Connie resolves to solve the mysterybehind Scarlet-s untimely death...and in the process, uncovers aconspiracy that still haunts the present!