Allnighters aren't continued in 2014. The following text is for archives only.
In addition to video evenings, Otakut watch anime in allnighers. Allnighters are, as the name suggests, events that last whole night. We start watching in the evening, and watch until the next morning. Program includes episodes from series, mini movies and normal movies. Series shown on allnighters are not continuations to video evenings, but they might continue from a previous allnighter. Like video evenings, allnighters are only for members.
Allnighters are usually held at the multipurpose room of JMT 3A. If you plan on staying the whole night (no-one forces you to), it's good to prepare accordingly. There are basic chairs, but many have found that a mattress or similar is much more comfortable. A blanket and a pillow can also be very nice, especially if you get tired and take a nap in the middle.