The Porno Book is a Key Item found in the Labyrinth of Chaos by wishing to the dragon in the Dragon Wish special floor and asking for a Porno Book. Unlike most Key Items, it can actually be used, which will prompt a reaction from certain party members.
Detail
A book so erotic, your right hand moves on its own!
Effects
"Using" the book will cause Luka to open up the book and a random party member reacting to this. Only important party members will react, this includes Alice, Ilias, Sonya, Nuruko, Hild, Promestein, Chrome, Eva, Saki, Sara (Both forms), Alicetromeria, Eden, Lucifina, Micaela, Heinrich, Morrigan, Alma Elma, Bonnie, Tetsuko, Tama and all four spirits.