Because who doesn't like loli spiders? For only being one episode I thought it was pretty good.
MyAnimeList.com wrote...
Wasurenagumo is one of the four anime works that each received 38 million yen (about US$470,000) from the "2011 Young Animator Training Project." Just like in 2010, the animation labor group received 214.5 million yen (US$2.65 million) from the Japanese government's Agency for Cultural Affairs, and it distributed most of those funds to studios who train young animators on-the-job.
As for the plot it centers around Suzuri, a man running a antique book store, and Mizuki, the landlords daughter who collects Suzuri's rent. One day Mizuki opens a sealed book in Suzuri's collection that contains an adorable little spider girl.