Very cute game of vampire world and relationship building! Gakuto for instance warming up as you go was really touching. Plus building trust for the donation part. (Or not if you pick that of course. :P) That also sounded like what I heard regarding actually donating blood so it should do a good job telling others what they will experience. Well, besides the vampire bite part of course, lol! Though I have also heard there's something similar where they numb the area before a stick. But I haven't experienced the process myself because I have always been too nervous (I am very weak to pain plus have anxiety) to try donating.
Not too many paths to take through it though. Whether you get perfect scores or not doesn't alter the dialog much for instance. (But will reorder or skip the re-quiz of course)