Atama Yama

Both of them are made by the same studio (Studio DEEN) sou the animation stile is identical. Both of them have weard plot lines. 

Both are short anime with a bit surreal feeling and the idea of small world existing in a common place (on a top of someones head/in a book) and both have very similar animation done by the same person. Both were made by same director. 

Similar storytelling style, with rōkyoku narration and shamisen played by Takeharu Kunimoto. Though they have very different animation style.