Prologue: Mosquiton and a girl with long red hair in a long yellow dress are embracing on a battlefield.
Cowled men ask Mosquiton if he will betray them.
Mosquiton walks past the girl into a room where he's impaled by a glowing cross. With his last breaths he promises to return for her.
The girl is holding a book and agrees to something (we don't know what) that will, apparently, send her race to hell.
Cut to the present day. In New York, a strange pyramid appears, followed by other bizarre monuments cropping up all over the world.
Inaho Hitomebore is the star student at a Catholic girls' school. She's intelligent and athletic, and admired by all the other girls. She isn't exactly what she seems, though. After leaving her classmates, she retires to a secret room full of computers, where she begins her daily routine of making money (she's a little obsessed). She sees the strange monuments on the news and realizes that they match a prediction in her grandmother's magic book.
Meanwhile, a strange jewel hovers over the school. Light shines down from it onto the main square and a coffin appears in the light. Out of the coffin, of course, comes Mosquiton. He proceeds to snack on the schoolgirls until Inaho spots him. She's thrilled; for some reason she thinks that a vampire will be great for making money. I think she wants to use him in a theme park or something. -.-; Anyways, she runs around collecting anti-vampire stuff and confronts him in the school chapel. When she realizes she's no match for him, she gets scared and starts running. Mosquiton, Hono and Yuki chase her up to the bell tower, where he's just about to kill her when he has a flashback where he sees the girl with long red hair, standing near a castle....and she looks just like Inaho. While he's distracted, Inaho takes the opportunity to grab a sharp piece of wood. Hono and Yuki shoot fire and ice at her, but Mosquiton jumps in front of her to block the blasts...and at the same moment she stakes him. He falls over in a pile of ash. While Inaho's still in shock, the strange blue jewel comes down from the sky into her hand.
In a dark room, an old man with a long beard (Rasputin, of course) is watching images of the weird monuments on many videoscreens.
Cut to the main square, where Inaho's reviving Mosquiton with a drop of her blood.
The next, day, Mosquiton (looking very cute in white shirt and suspenders) is introduced as the new history teacher.
Mosquiton has a little apartment now, and we get to see him waking up in the morning. He's REALLY not a morning person; it's a very funny sequence. When he gets to class, he finds tht all of his students are in love with him and keep sneaking love-letters to him. He's understandably flustered. Apparently anybody he bites falls in love with them...kinda inconvenient.
Meanwhile, Inaho was fooling around with her book and the magic symbol that's now in the main square, and accidentally summoned a manticore. She orders Mo-chan to go fight the manticore. Just as he's about to send it back where it came from, Inaho sees a jewel in its tail, one that's identical to the one she has. She jumps into the magic circle and is transported somewhere else. Mo-chan goes to rescue her, against the advice of Hono and Yuki.
Inaho finds herself in an ancient Greek temple with harpies sleeping along the ceiling. She sneaks her way through it, but just HAS to take a jewelled vase lying on the ground. And of course this wakes up the harpies, which start attacking her. She escapes into another room with a glowing ball which turns out to be an oracle. It tells her that this is another world, one where all the monsters and monuments come from, and that it's connected with her world through the O-parts. Whoever gets the O-parts, apparently, gets power and gold. But just as it's about to tell Inaho where the O-parts is, it's smashed by the manticore. Mosquiton shows up just in time to kill the manticore, and Inaho notices that inside the broken oracle there's a keyhole. She takes her jewel (which she's wearing in a pendant now) and inserts it into the keyhole...at which point she gets electrocuted. The oracle says 'If the O-parts don't match, you will receive a punishment'.
Mo-chan, Hono and Yuki are grocery shopping. Just outside the store, they're met by a butler-type fellow with a limousine, who takes them to Inaho's mansion. She's very rich...which makes one wonder why she's still psychotically chasing after money. Anyways, Inaho shows Mo-chan an ancient Egyptian papyrus that talks of O-parts buried in a particular pyramid...except she only has half the papyrus, and it doesn't detail exactly where the O-parts are.
So they head off to Egypt, where they find a crew of army guys excavating the pyramid. A weird sphinx attacks them, and Mo-chan chases it off. To thank them, the expedition leader, a busty woman with purple hair, invites them to have dinner in her tent. She says they're digging 'for vases'. During the night, however, she tries to steal Inaho's necklace but is chased off by Mo-chan. When Inaho goes into the woman's tent, there's nobody there...but she finds in a notebook the other half of the papyrus. The purple-haired woman is also after the O-parts so she can become human (she turns into a werewolf whenever she's touched by a man) and agrees to work with them to find it.
The next day, Wolflady and Inaho go into the pyramid, while Mo-chan agrees to stay behind and watch out for the sphinx. Wolflady has arranged for him to be buried alive, however, so he won't interfere. While in the pyramid she leaves Inaho behind to die, but of course she's rescued by Mo-chan in the nick of time. They finally get to the king's tomb and take the O-parts, but the sphinx attacks and Mo-chan has to fight it again. Wolflady is touched by one of the army guys, and goes wolfy. She attacks Mo-chan, they fight, he beats her. Inaho gets her hands on the O-parts and inserts her key, but the O-parts are fake and they disappear. The pyramid starts to fall apart around them. They all escape back to the school, where Wolflady becomes Ms. Ogami, the new gym teacher.
Mo-chan, Hono & Yuki are house hunting because they hate their little apartment. It's a very funny sequence; watching the real estate agent's reactions to their 'ideal house' is great. Inaho, however, won't raise Mo-chan's salary, so he can't afford a house.
While at a coffee shop, they see a news report about monsters at a haunted castle in England (with a rather un-spooky name, 'Jerry's Castle'). So Mo-chan, Inaho and Wolflady head over to England, where they're attacked by a freaky guy with a chainsaw who chases them all over the castle. He turns out to be Franky Negger, a frankenstein-type monster who's a big fan of Wolflady, and was only chasing them because they had his copy of a monster magazine with ecchi pictures of Wolflady in it. Franky was created by Dr. Jerry, a mad scientist (who looks like a robot) who captures our heroes to use them in monster experiments. Wolflady gets Franky to let them go (he'd do anything for her) and destroy Dr. Jerry. Inside Dr. Jerry they find what looks like an O-parts, except it turns out to be Franky's tape diary where he babbles about how much he loves Wolflady. They all head back to the school, where Franky's now the biology teacher. (sensing a theme here?)
Inaho, Mo-chan, Hono and Yuki head over to Easter Island to investigate the statues there. They find dancing statues, and inside a mysterious building there's an O-parts keyhole. Inaho uses the keyhole, but nothing appears to happen. Then a tiny little statue (a moai) appears with a red hat. Inaho thinks it's the cutest thing, names it Ai-chan and takes it home with her. After they leave, a portal opens in the Easter Island building and many statues start to come through it.
Back at the school, Mo-chan's about to close the magic circle but Inaho's late for class and doesn't let him. Inaho has lots of fun showing Ai-chan off to her classmates and having him do tricks. While everyone's in class, hundreds and hundreds of statues start coming through the portal and running around the school, harassing the girls and generally causing mayhem. They just keep coming and the school is in chaos, until finally Mo-chan goes back to Easter Island and breaks the statue portal, at which point all the statues stop moving. Ai-chan changes shape and becomes a sort of monkey-thing, for no discernable reason.
While his class is taking a test, Mo-chan has a nightmare about fighting demons on a battlefield.
Inaho wants them to go to another mysterious ruin place in search of the O-parts, but she's sick and Mo-chan tries to convince her to stay home. She doesn't listen, of course, and they head out...with him carrying her most of the time. Hono and Yuki agree to go on the expedition, in hopes that Inaho will die. They get to the ruins where they're attacked by a bunch of soldiers, and spend some time running around getting shot at.
In the dark room with the videoscreens, Camille is reporting to Earl St. German about their research on the O-parts. Earl expounds on his wish to rule the world and 'bring eternal darkness to the future'. Earl appears to control his henchmen, including Camille, by holding jewels that are linked to their life-forces somehow. Camille reports that Mosquiton is at the ruins, and Earl sends a fellow named Hound to deal with him. Mo-chan fights him and defeats him. They get the O-parts, but all it does is dump water on Inaho.
A bunch of thieves have broken into the ancient temple of Angkor-Wat in search of the O-parts. Just as they find them, a giant serpent-dragon, the guardian of the temple, attacks them and floods the temple with water.
At the school, Wolflady steals Inaho's necklace in the middle of the night, but it turns out to be fake - Inaho had anticipated this. Inaho informs her team about the dragon, named Nana, at the temple, and they all rent a boat and head to the temple. Mosquiton expresses some concern about bringing Wolflady along, consider her recent actions, but Inaho isn't worried because she has discovered Wolflady's secret weakness, something called the 'curse of silver'.
While Inaho's sleeping on the boat, Wolflady tries to seduce Mo-chan and drugs him, then chains him up and dumps him overboard. When Inaho wakes up, Wolf tells her that Mo-chan's still asleep and they go off to find the O-parts. They're attacked by the dragon, and when Inaho goes to 'wake up Mo-chan' Wolflady ties her up and has Franky watch her. Meanwhile, Mo-chan has woken up (at the bottom of the lake) and freed himself, but is having a bit of trouble with the dragon.
Inaho convinces Franky to let her go on the pretext that she'll let him kiss Wolflady. Wolflady is about to use the O-parts when Inaho reads out the 'curse of silver' from her magic book. Mo-chan, meanwhile, has killed the dragon. Inaho uses the O-parts, but it just dumps snakes on her (this seems to happen a lot, things getting dumped on Inaho). Inaho paralyses Wolflady with the curse, and lets Franky kiss her.
Inaho has coerced Hono and Yuki into cleaning her mansion; while they're cleaning Inaho finds a paper with information about some place named Shambara, where the O-parts can be found. She heads off to Shambara with Mosquiton.
Hono and Yuki are still cleaning, and find a large chest which turns out to be a box garden with a miniature temple in it. An instruction manual with it says it's the 'Shambara Box Garden'. Mysteriously, the temple that Inaho and Mosquiton find in Shambara looks exactly like the one in the box garden, but they don't know this. A cockroach falls into the garden, and at the same time Inaho and Mosquiton encounter a giant cockroach. Yuki dumps water into the garden by accident, and Inaho and Mosquiton are flooded. Yuki and Hono look into the garden and notice little dolls which looks like Inaho and Mosquiton. They really hate Inaho, so they have fun by poking at the Inaho doll and blowing fire on it and such (they don't realize it's really her). In Shambara, big things keep falling from the sky onto Inaho and fire comes from nowhere.
Now that they've had their fun, Hono and Yuki go for tea. While they're having tea, the butler sticks the box garden in the incinerator. Mosquiton and Inaho are about to get the O-parts when the temple starts burning and falling apart around them. While talking with the butler, Hono and Yuki realize that the box garden Shambara is the place that Inaho and Mosquiton went to, and race to rescue it from the incinerator. In the temple, Inaho and Mosquiton manage to get the O-parts and activate it. It brings them out of the garden and back into the real world, but Inaho's butt gets burned.
It's the school festival, and as expected Inaho's planning lots of money-making activities. A cousin of Inaho's, Akitakomachi, shows up to challenge Inaho. It seems that Inaho, as the eldest child, was chosen to be the head of the family and carry on the family name of Inaho, but Akitakomachi feels that she should have been the one chosen, as she was only born 5 minutes after Inaho. She launches all sorts of schemes to mess with Inaho's moneymaking activities in order to get Inaho to renounce her title, but in the end she leaves, promising to return and get revenge.
Inaho's class is returning from a school trip to South America, and as usual Inaho's smuggling valuable relics into Japan. She thinks she has a foolproof way of getting past customs (magically teleporting the relics into her house from the airplane bathroom), but she miscalculates and the relics end up being teleported to the airport bathroom. Meanwhile the Mask of Nazca, one of the relics, ends up being found by the fat girl Amanogawa. She tries it on and becomes possessed by the evil spirit. This causes the airport to be covered with sand and overrun with monsters, which Inaho and Mo-chan have to defeat. They find a fake O-parts, Inaho gets electrocuted as usual, the end.
It's winter vacation and Inaho has recruited Mo-chan, Hono and Yuki to repair the school. Inaho then decides to go to a desert palace to look for the O-parts. In the ancient palace she finds a sarcophagus, within which is a handsome prince named Solon who's been sleeping for 1000. Solon wants to marry Inaho, and she's thrilled as she's always dreamt of marrying into royalty. All his subjects look like mummies for some reason--there's even mummy boxing and mummy elephants. Anyways, an ancient monster attacks (it's the reason the kingdom went to sleep for 1000), and Inaho decides to leave rather than sleep for another 1000 years until it goes away. Oh, and she finds another fake O-parts and gets electrocuted. Again.
As you may be able to tell, I'm getting really sick of these dumb premises. Every episode, a pointless and nonsensical setup for Inaho to find a fake O-parts, she gets electrocuted. I'm not sure if I want to sit through any more of this show...