Reeve Ekin Cheng is an ace vampire hunter who has just lost his third assistant to some nasty European vampires. Especially their leader, Duke Dekotes Mickey Hardt, with his pointy teeth and superstrengths, determined to bring a new age of darkness upon the earth. Fortunately, Reeve can keep up with them, thanks to the banana-flavored antidote that gives him vampire powers for 90 minutes after drinking. He just has to remember to drink it by the end of that period or risk turning into a vampire permanently.Reeve's innocent sister Helen Charlene Choi , a fiesty young beauty, just caught her boyfriend cheating on her, having dinner in a restaurant with another girl. After teaching the bum a thing or two, Helen collapses at a table occupied by two guys and swigs down a glass of their wine. What Helen doesn't know is that the guys are the Fifth Prince of the Vampire Nation, Kazaf Edison Chen, and his attendant Prada Anthony Chau-Sang Wong, that they are both vampires, and that the wine she just drank is actually blood. Fortunately, Helen is too upset to notice the taste, and Kazaf is so charmed by her that he instantly falls in love, so much so that he asks for her phone number. Prince Kazaf isn't one of those common vampires who suck blood out of people's necks. In fact, his dad sends him a case of Chateau Grimon blood every week. Kazaf and Prada live in a church, and Kazaf's coffin is a marvel of high tech accoutrements. What Kazaf doesn't know is that the Duke has been killing off the royal family in order to obtain their blood essences so that he can open the book Day for Night and obtain the blood of the ultimate vampire, which will allow him to go out in the sun. Prince Kazaf is the last one left of the royal family. Before his father, King Morgun, was assassinated, he sent the book to Kazaf for safe keeping.When the Anti-Vampire Federation sends over a replacement partner for Reeve, he sends the new girl, Gipsy Gillian Chung, up to the roof to meet his sister. Helen is tossing out everything her ex ever gave her, but Gipsy can't bear to see her throw out a big, cuddly teddy bear, so the two have a kung fu fighting match over it on the roof top. But Helen is getting over the bum pretty quickly, especially after Kazaf calls her and asks for a date...at noon tomorrow. No problem for Helen, but a big problem for Kazaf, who cannot go out in the sun. But Prada has an idea. Two thousand years ago, Sir Nicholas of Poland concocted a sunscreen that allowed him to tolerate sun. Fortunately, Prada has the recipe. A little absinthe juice, extra virgin olive oil, red wine, sesame glue, and potassium, all mixed into a blob of face cream, baked in the oven for an hour and then placed in the sun for a century. Well, maybe three hours will do, but it surely won't be as strong. That afternoon, Kazaf, slathered with sunscreen, keeps his date with Helen. She crashes the wedding of Jackie Jackie Chan and Ivy , but it turns out to be a good thing. Jackie's best man has lost the ring and Kazaf is able to substitute his vampire ring at the last minute, saving the marriage. The next night, Helen shows up on Kazaf's doorstep with a gift of home-baked banana cake. On their first assignment together, Gipsy and Reeve run out of antidote. They hurry home for more, only to find that Helen has just baked it up into a bunch of banana cakes. Reeve is forced to eat the entire batch, but it does save him from turning into a vampire.When it becomes obvious that Kazaf is in love with Helen, Prada warns him that he must tell Helen about his vampirism. When he does, Helen doesn't believe it. She thinks Kazaf is just trying to dump her because he thinks she's too pushy and has a big mouth. Besides, Helen also has a problem with the relationship, but before she can tell Kazaf that her brother Reeve hunts vampires, Kazaf faints. It seems that, since his father's assassination, the King has stopped sending blood, and Kazaf is starving. Helen has an idea. She takes Kazaf to the nearest hospital where they steal two pints of blood from the bloodbank. Unfortunately, the vampires have the same idea, which leads to a wild chase - vampires chasing Helen and Kazaf who are riding in an ambulance driven by groom Jackie, who has turned out to be an ambulance driver. Helen and Jackie save the day when Helen squirts blood into the vampires' mouths and Jackie shoves handsfull of antidepressants down their throats. The vampires are left dancing in the streets.When Helen gets home, she finds Gipsy ironing Reeve's shirt. It seems that Gipsy has also fallen in love with Reeve. Helen and Gipsy iron out their teddy bear fight over a box of Cornflakes, and Helen begs Gipsy to speak to Reeve about the fact that Kazaf is a vampire. When Reeve finds out, however, he becomes irate and heads over to the church where Kazaf lives. Meanwhile, the Duke has also found the church and is waiting there for Prince Kazaf to return but is pleased to capture Reeve, too. Gipsy races home to get help from Helen and Kazaf. Kazaf, holding a knife to his own chest and promising to spill his own blood (which will neutralize his essence), orders the Duke to let Reeve go. The Duke refuses and offers the life of Prada instead. Kazaf doesn't know what to do. He refuses to drop the knife, so the Duke kills Prada. The Duke then forces the vampire essence from Kasaf, uniting it with all the other essences and using them to open the book.Meanwhile, Gipsy and Helen search for Reeve. When they find him, however, it's too late. Reeve has taken the vampire extract, but the antidote has gotten spilled. Reeve has already turned into a vampire. Reeve tries to strangle both girls, but Gipsy is able to stab him through the heart. Reeve dematerializes, and Gipsy and Helen cry. But not for long. There is still the Duke and his minions to take care of. Gipsy and Helen attack in full strength until only the Duke is left. When Gipsy suddenly finds herself in possession of the ball of essence, she swallows it. Gipsy turns into a vampire and goes hand-to-hand with the Duke, but it's a well-directed plunge of Helen's sword that finally destroys him. Once the Duke is gone, Gipsy becomes human again.Epilogue: Gipsy, Helen, and Kazaf have formed a new team of vampire hunters. [Full synopsis by bj_kuehl]