Onimonogatari (2015)

All four episodes from the Japanese anime adapted from the light novel by Nisio Isin. When Shinobu's past comes back to haunt her in an unidentifiable form known as the 'darkness', her friends Araragi, Mayoi and Yotsugi help her to avoid becoming a victim. However, it seems there is more going on than first meets the eye. The episodes are: 'Shinobu Time: Part 1', 'Shinobu Time: Part 2', 'Shinobu Time: Part 3' and 'Shinobu Time: Part 4'.