Goofy, childish folklore scholar Kantarou Ichinomiya (the English translation uses Western name order) ekes out a living by writing books from his research, but his actual passion is encountering and befriending youkai. In his youth, his ability to see youkai caused him to be shunned by other children, and he became convinced that his problems would all be solved by finding the famous demon-eating tengu (a classic Japanese monster with birdlike characteristics, although the only birdlike thing about the two tengu seen so far in this series are their feathered wings). When Kantarou finds the tengu in the opening chapter of the series, he binds the creature by giving him a name, Haruka. The handsome humanoid becomes part of Kantarou's household, along with a fox youkai woman named Yoko who serves as cook, maid, and menial-of-all-work. She's the one who has to go out and earn them all a living when Kan-chan's slacking off.
The outline of the story sounds roughly like Natsume's Book of Friends, but notice that Kantarou is binding youkai, not releasing them. Also, instead of the touching, lonely little child Natsume that we see in flashbacks in that series, li'l Kan-chan is an absolute parody of a cutesy manga tot, and the English translation has him speak in the kind of twee childish lisp that Dorothy Parker parodied when she said (in her review of The House at Pooh Corner) "Tonstant Weader fwowed up." Kantarou is feckless, bossy, has no sense of boundaries, can't seem to acknowledge that he has enslaved Yoko and Haruka, and does things like drag them off to a hot springs resort (paid for by his editor) and then complain that they still look sulky.
Man, do I want to smack the living shit out of him.
I disliked him rather less on my re-read before writing this, enough so that I ordered the rest of this shounen series secondhand (Tactics was a victim of Tokyopop's demise and ends in official English translation with volume 8). The plot mainly involves Kantarou's investigations of strange phenomena that typically turn out to involve youkai. Sometimes things end relatively happily, but when they don't, Kantarou proves himself a true cousin of Yuuko (xxxHolic) and Count D (Pet Shop of Horrors) in arranging for unpleasant fates for the wicked.( Cut for more, including some spoilers )