Keita Kawahira is one of a family of Inukami users - a clan who makes contract with the titular dog spirits in order to protect the local populace from evil spirits, and deal with specific supernatural threats for a price. His cousin Kaoru already has 10, and the time has come for Keita to get one of his own. He finds himself partnered with Youko, a feisty type with an inclination to throw fireballs. With that setup, a series begins full of violence, cuteness, perversity, and dogs. Keita tries to get on the good side of Kaoru's Inukami while he's away, and Youko tries to keep him in line.A fun series, if on the strange side at times. Compare with Akikan!, as they were both originated in light novels later adapted to anime.
Inukami! provides examples of:
Batman Gambit: One episode featured the inukami plotting to take advantage of Keita's perverted tendencies, sure their plan would work immediately. Except he showed restraint, foiling their plan.
Battle Couple: Youko would like to be this with Keita, and from the perspective of EVERYONE ELSE they are. Keita himself only sees her as his monster busting partner.
Beware the Nice Ones: When Kaoru is hurt, Nadeshiko turns brutal and releases the fury she's been holding back after she murdered a avillage long ago.
Big Bad: Sekidousai, whose inventions form the basis of early plots and those Evil Plan drives the second half of the show.
Bigger Bad: Jesei is more powerful then Sekidousai and is the final boss but had nothing to do with the bulk of the plot.
Big Damn Kiss: Keita kisses Youko in the climax, as they fly toward the Bigger Bad, undeniably returning the affection she's showed him the entire series.
Bishōnen: Keita and Hake, as well as most other male characters who isn't macho men or Gonk.
Blinding Bangs: Tensou for shyness. She doesn't talk except through pictures
Blond Guys Are Evil: Sea of Violence and Sekidosai are both blonde villains. None of the heroes are blonde.
Censor Box: The elephants, they're on parade. Usually right around the crotch area and usually on Keita.
Chain of Command: You'd think it'd be on Youko, but it's Keita who wears the collar around his neck.
Cheerful Child: Tomohane is the youngest in the harem and consistently in good spirits.
Chekhov's Gunman: Remember the kappa that hung out in the background? He saves Keita in the climax.
Chivalrous Pervert: Keita, and those four Citizens of Darkness guys who he often share a jail cell with, are in jail for their preversion: public nudity, panty stealing, etc. Other than that, they're ok people.
Clingy Jealous Girl: Youko will not tolerate Keita showing interest in other girls and when they're together she's likely to grab his arm or some other affectionate gesture.
Conservation of Ninjutsu: Averted. Sendan's group, even as a whole, is less powerful than Youko is by herself but they're even worse off when fighting individually. Youko is just that much more powerful than they are.
Evolving Credits: The start of the ED changes to reflect wherever Keita and Youko are at the moment.
Expy: A Cute Monster Girl with green hair falls in love with a preverted human boy and punishes him for chasing other girls with her superpowers. Does this describe Youko or Lum?
Fanservice / Fan Disservice: It's often very hard to determine whether it's the former or the latter. The latter much more than the former since that is where much of the show's humor comes from. The former is so few in comparison that one tends to forget that there's any fanservice at all. Part of this is a lot of the fanservice is directed to the girls... much to Keita's chagrin.
Flash Step: Nadeshiko when she gets serious she can move extremely quickly.
For the Evulz: Sea Of Violence claimed that he made contracts with humans who want wealth at the price of him taking their (and their descendants') souls when they reach a certain age, just for the fun of it and he particularly enjoys curb stomping all of their attempts to stop him from taking their souls.
Gondor Calls for Aid: When the main cast can't defeat a Humongous Mecha, Kawarazaki calls to the all the preverts and nocturnal lurkers of the city and they Zerg Rush the thing. It's not quite The Cavalry because Keita still has to finish it off and defeat wasn't immiment. Among them are the Panty Thief, Dr. Peeping Tom and the chief clerk. Really, almost every named character so far introduced is part of it.
Grim Reaper: Shinigami appear to be a natural enemy for the Inukami.
Harem Genre: In this case Keita, the main character, is not the one with the Harem. His much more talented cousin has a harem of dog girls but this doesn't stop Keita from trying to steal them. It's ultimately a Downplayed Trope as they become more friendly with him over the course of the series. They still prefer Kaoru over him, of course, but there's a definite change of attitude.
Immortal Immaturity: Youko is more than 300 years old, but still acts like a spoiled little girl. Her father Dai Youko is no better - Hake even says, after describing his terrifying powers: "He's just like a child. No, it's even worse because he's an adult." note Yohko's father spoiled her but the time frame implies she would've had to be alone for long enough that she shouldn't be so bratty especially since her time on the mountain with the Inukami was supposed to be a miserable experience.
Keita has many of these moments. When he first meets Youko, he loudly fantasizes about how she would cook his meals, clean his house, and perform other services for him. Even later on, he constantly refers to her as only his "dog". note The cooking and cleaning and whatnot apparently is in the job description, but Youko's ego is too big.
Yohko: it's stated Keita is the black sheep of the family because he couldn't get an Inukami. Turns out that when Keita went out and was supposed to find an Inukami as part of the coming of age ceremony for his clan Yohko scared them all away so years later she could force a contract between the two while threatening to kill him.
Laughably Evil: Many of the villains are funny but they are FAR from harmless.
Made of Iron: Not only can Keita take the Dai Jaaen, but villains have difficulty hurting him.
Man Behind the Man: Jesei was this to Sekidousai, though he's more of a Bigger Bad since they had completely seperate plans and the latter isn't even foreshadowed until an Info Dump in the third to last episode. However, the trope is fulfilled because the former hijacked the latter's plan.
Poke the Poodle: Youko during the fight with Kaoru's inukami; Tomohane was caught outside the shield they made and Youko put a finger on her forehead, but instead of attacking her, Youko (using magic) took off her panties instead.
Public Exposure: Sekidosai is an exhibitionist (unlike the others, he has a Mammoth censor instead of everyone else's elephants) and he hates it when forced to put on underwear.
Red Baron / Embarrassing Nickname: Keita is better known as "King of Nudity" among the Citizens of Darkness than his own name, though he's horribly embarrassed by it.
Scary Shiny Glasses: Kawarazaki, Chief Clerk and Sea of Violence as well. The first two are creepy (yet pleasant) pervets and the later is an evil spirit.
Sealed Evil in a Can: Dai Youko, Sekidousai, Youko too were all sealed away at one point. Youko is asked to keep Dai Youko sealed.
Silent Bob: Tensou. She communicates with others via rapid, well done sketches.
Xanatos Speed Chess: Youhko played an impressive game when the Kawahira family tried to reseal her dad. when straight up sealing failed she told him she was living together with Keita and having sex every night. He mellowed into a happy future grandparent who'd like to keep the world in one piece for their sake. Thus she turns a possible End of the World as We Know It into a wedding for herself and Keita.
Nadeshiko. She's sweet, domestic, and even refered to as 'traditional japanese girl' by Keita. As per the trope, she has the inner iron to call him out on being an asshat and invoke Go Through Me when Yoko is about to kill Sendan.
Hake counts as a male example because he dresses in a traditional clothing, is always polite, never a pushover and devoted to his partner.
Your Approval Fills Me with Shame: Keita is disgusted by the genuine respect minor antagonists like underwear theif and Peeping Doctor show him and can't stand the title they refer to him with: King of Nudity. Although he IS just as perverted as they are, and did such an act in the episode, the title is actually Yohko's fault.
Zerg Rush: How those Citizens of Darkness people brought down Xanthippe, and later Jasei's undead minions.