Kyoukaisenjou no Horizon: Kyokutou Naruhodo Kouza
Kyoukaisenjou no Horizon Specials
境界線上のホライゾン 極東なるほど講座
Specials aired on Nico Nico Douga and YouTube, later released on BDs/DVDs.
Specials aired on Nico Nico Douga and YouTube, later released on BDs/DVDs.