Set in Akihabara, the shopping area has been invaded by creatures known as "Synthisters" who prey on the patrons of Akihabara like vampires, feasting on their social energy and will to live. These enemies can only be stopped by direct exposure to sunlight, meaning that the player is required to defeat these demons by stripping off their clothes and exposing them to sunlight. The storyline revolves around a conspiracy behind the Magaimono organization that the player explores. Within the game, there will be over 130 real life Akihabara shops that the player is able to visit.
The game features collaboration DLC in the form of character costumes and equippable items, including those from Ragnarok Odyssey Ace, Disgaea, Hyperdimension Neptunia, The Legend of Heroes, Super Sonico, and Genshiken.
Source: Wikipedia, "Akiba's Trip: Undead & Undressed", available under the CC-BY-SA License.