There's a school built on a Hellmouth... well, at least something like it, a conflux of mystical energies that makes all sorts of screwball things happen. Like how anyone who jumps in the fourth lane of the swimming pool instantly drowns. How there are horrible monsters here and there in the school. And ghosts. And magic mirrors. And stuff. To keep this all under some semblance of control, Chairman and owner of the school Tatsuyuki Saitou has organized the children of the local clergy into the Holy Student Council.
The main character of this anime, Haruto Houjou, is the son of a minister and president of the student council, a position he desperately wants out of. His first appearance onscreen is his first attempt to bow out of the presidency. He's fed up with the insanity. He'd like to transfer to a different school. The principal won't let him.
Also on the Holy Student Council is the son (or grandson, if you follow the manga) of a local Buddhist monk, Kazumi Ryudo, who specializes in getting possessed by various spirits, especially animals, and is constantly lusting after the bathroom spirit Toilet Hanako. There is also Mutsuki Asahina, a strongwilled and redhaired miko (daughter of a local Shinto priestess) with an extreme Shotacon. Neither of them are particularly sympathetic to their president's desire to leave; they think it's cool to have all this weird stuff going on, mainly because they get to cut class and slack off during school hours.
The story quickly heads to a Gotta Catch Them All wherein the trio hunt down... badges? Little round badges that can be used to summon seven spirits (well, one of the spirits is two distinct spirits that work together). These spirits include:
- a giant (you only ever see his legs);
- a Magic Mirror with a young girl in it;
- a living statue of Ninomiya Sontoku who looks like a cute little boy;
- a masked White-Haired Pretty Boy in red who haunts the ladies' room (and may be a homage to Tuxedo Mask);
- Toilet Hanako, the the beautiful girl ghost who haunts the men's room;
- a skeleton and anatomical model;
- a living Beethoven portrait that cries Tears of Blood (manga only)
- ... and the chairman himself.
After they've all been caught, the main character ends up using the spirits to try to drive out various supernatural forces that enter the school, from the ghost of a dead cartoonist to some far scarier stuff...
- Absurdly Powerful Student Council - Parodied oh so much here.
- Building of Adventure - Saitou High School, because of its location, attracts ghosts like whoa and no one except for Haruto seems to bat an eyelid. Once they pass the infamous entrance exam, which involved the ghosts helping the Council to organize and set up the examinations (it's all in the manga), students seem to really not mind the presence of the ghosts (and some ghosts, like Red Mantle and Hanako, have lots of fans). Also, ex-students sometimes go back running to it when they have problems, rather than going to shrinks or their families; when asked, the Chairman tells the Power Trio that Saitou high is a haven for kids in trouble, where they can just be heard and feel welcome.
- Cain and Abel - Red Mantle and Blue Hanten
- The Can Kicked Him - at every single Japanese High School.
- Captain Ersatz - Art Room Ichiro's "Sailors XO" manga characters are clear imitations of...guess who. Also used to highlight Red Mantle's similarity to another character in the same show...
- Catch Phrase - Haruto Houjou: "OH MY GOD!!!"
- The Complainer Is Always Wrong - Haruto, Haruto, Haruto...
- Crystal Dragon Jesus - The kids' religions play a vital role in the story, but this doesn't mean they'll be faithfully portrayed.
- Curtains Match the Window - Some of the character's eyes match their hair color.
- Even the Guys Want Him - Red Mantle when unmasked
- Expository Hairstyle Change - Haruto's blond hair grows longer as time passes. Mutsuki pulls her red hair up in a ponytail when in Shinto garbs.
- Failure Is the Only Option - Haruto won't ever be able to resign.
- Fetish - Lampshaded with scenes that cater to both Kazumi and Mitsuki's tastes.
- Four Is Death - It's said if you jump into lane 4 of the school's pool, you'll drown instantly.
- Flung Clothing - Mutsuki changes from her uniform to her Shinto robes like this.
- Genius Ditz - Minister Hojou, aka Haruto's father, is a rather efficient and kindhearted minister... but he is a complete Cloudcuckoolander and, in the anime, fond of dressing up in animal costumes.
- Genre Savvy - The Chairman is a ghost, knows he's a ghost, and often explains all kind of stuff to Haruto. Mutsuki and Kazumi are also Genre Savvy, to a degree.
- Ghostly Goals - A frequent plot device with ghosts that need the Holy Student Council to get them to their rest.
- Grand Theft Me - Parodied: Kazumi's psychic powers allow him to be repeatedly and easily possessed by ghosts.
- He Who Must Not Be Seen - The Dancing Giant
- Honest Axe - The giant scissors
- Identical Grandson - In the manga, Kazumi looks very much like his grandfather Taro's younger self.
- I Have Your Wife - Yamiko forces Hanako into a duel by kidnapping others (Haruto, in the anime; Mutsuki and Sontoku, in the manga)
- I Just Want to Be Normal - Haruto really, really wants this in the anime. Subverted later: when he does get his wish, he sees that a normal life isn't all he thought it'd be...
- Let's Get Dangerous - For all his complaining and goofy overreactions, Haruto is hypercompetent when he decides to buckle down.
- Loony Friends Improve Your Personality: Explicitly the plot of the series, as per the finale.
- Lovable Sex Maniac - Kazumi
- Marshmallow Hell - Hanako and Kazumi She once de-brainwashes him through this
- Ms. Fanservice - Hanako and Yamiko
- My God, What Have I Done? - After Haruto summons the school spirits in order for them to be exorcised. Comes with a fair bit of What the Hell, Hero? from Mutsuki and Kazumi.
- Power Trio - Haruto, Kazumi, Mutsuki
- Shotacon - Mutsuki prefers her boys younger. That makes her the only girl in Saitou who's immune to the charms of Red Mantle.
- The Strategist - When Haruto stops whining about wanting a normal life, he shows impressive wits and capacity to think and plan things under fire. This prompts his Crowning Moment of Awesome from the second anime episode.
- Trickster Mentor - The Chairman, to the Power Trio
- Tsundere - Mutsuki is a Type A.
- The Only One Allowed to Defeat You - Yamiko, to Hanako
- The Vamp - Yamiko
- Yoko Oh No - The female ghost Hanako-chan, in episode 3, died because she was running away from her rock star boyfriend's rabid fanbrats and was accidentally hit by a car. They get their asses kicked very literally by the Giant and the other Saitou Ghosts as punishment.
- You Have 48 Hours - Hanako-chan (no, not Toilet Hanako) will disappear into nothingness if she doesn't get her wish fulfilled by Kazumi