We have Holic and Bakemonogatari who are both mystery and supernatural genre.
Starting from this, both series can be considered somewhat similar. Here's why:
- both deal with strong supernatural elements who leads people (clients) in asking for help to someone who understand those phenomenons.
- both have a "supernatural expert" (Yuuko for Holic and Oshino Meme for Bakemonogatari) who are very good in what they do, usually always show a calm demeanor but as well are quite enigmatic to read and full of mystery.
- both series have quite particular main characters, who are definitely not "the average type of character" you often find
Well, let's see... Mysteries, or the so-called oddities in Bakemonogatari somewhat coincides with the cases that Yuuko solves in xxxHolic. And their way of solving these cases are quite similar too in a way that they derive complicated solutions to get the situarion done.
Both series revolve around supernatural afflictions and the ways to cure them.
Both series focus around the main character solving "oddities" or supernatural phenomena that occur with other characters. There are also parallels between the mentors of each main character. Yuuko (xxxHolic) & Oshino (Bakemonogatari) both provide insight as to how Watanuki (xxxHolic) & Araragi (Bakemonogatari) can solve the ailments spotted. Main difference is that in xxxHolic the solving of these oddities is more of price for service to customers, whereas in Bakemonogatari, the service is free of charge and deal with the protagonists close friends. Still both are enjoyable to watch and offer a lot of humor.
Both have similar supernatural things that the main characters have to deal with. both the main guy is somewhat attracting "oddities" and is surrounded by supernatural phenomenon and there's an adult who is the expert at dealing with it. Both anime's are good. Must watchXD
Both anime relate supernatural phenomena with everyday problems. Both also have a seemingly normal protagonist, who tries to help people who are involved with the "oddities". Both also have some sort of specialist in the supernatural stuff.
Both series features the protagonist dealing with the supernatural.
Both series has a unique cast of characters.
Both series contain humor expressed in a different way.
Both series contain heavy dialogue usage.
Both series involves many interactions with the other characters.
If you like youkai, supernatural, you will like it. Although xxxHolic is a bit more "focused" into supernatural thingy.
Although Bakemonogatari and xxxHolic have completely different plots, both main characters deal with strange abberations. Both Araragi and Watanuki have a sort of teacher that they turn to when help is needed (Meme and Yuko). Also, both animes have interesting dialogue with very interesting characters.
Both anime are quite different from others because of several factors. They use mysticism and Japanese folklore to develop the atmosphere of its history which makes it completely magical and surreal.
Both series feature a form of spiritualistic view of the world and people rooted in japanese folklore. Such as characters feelings and problems take form or are caused by an appiriration or spirit. The main characters are faced with theese situations and deal with them by helping the people resolve their problems. or not. Both series also featrure at least one character who is very cryptic and mysterious.
With a touch of supernatural, Bakemonogatari is an anime that feels a lot like the first season of xxxHOLiC. With progression in arcs the comedy, feel, and life lessons are both very similar in both of these anime.
Both series deal with supernatural beings and how humans interact with them. Nisio Isin once wrote a xxxHolic spin-off, so it's not a stretch to say that Bakemonogatari was inspired by it.