An apprentice succubus who has to take an exam to make a specific man ejaculate 10 times in order to be promoted to a full succubus... And the young man chosen as her partner has a problem with ejaculation. Despite the high difficulty of the exam, the succubus somehow succeeds with amazing technique and a tight pussy that guarantees ascension, unique to succubi, and the young man improves his ejaculation problem with that play... However... if she sucks out all of his life force (vitality), the young man will die... What will the two decide...?