I can't remember what this is even about

Basically about a vampire, princess (i think)and a knight and one more character who reincarnated in the modern world where they're no longer needed since the times are different. The vampire kinda is obsessed with knight(i think due to his blood), slowly they grow closer and the story just ends on some cliffhanger without properly disclosing their relationship.

Starts off good and ends kinda okish