Harem battles in the alternate world are recommended as follows: 1.<<Index of Forbidden Magic Books>>: This is a harem, battle, and fantasy anime with the theme of science and supernatural power. It tells the story of the protagonist, Dangma Shangjo, who fights and loves various beautiful girls in a world with the power of the Index of Forbidden Magic Books. "Sword Art Online": This is a harem, battle, and fantasy anime with a virtual reality theme. It tells the story of the protagonist Kirito and other players 'adventures, battles, and love in the virtual world. 3."Attack on the Giant": This is a harem, battle, and fantasy anime with the theme of the battle between humans and giants. It tells the story of the love and battle between the protagonist Alan and various beautiful girls as he grows up in the battle with the giant. 4 Fate/stay night: This is a harem, battle, and fantasy anime with history, magic, and love as its theme. It tells the story of the protagonists, as well as the battle and love stories between the various characters surrounding the Holy Grail War. 5 "Magical Girls Little Circle": This is a harem, battle, and fantasy anime with the theme of magical girls fighting. It tells the story of girls fighting, growing up, and falling in love in order to fulfill their wishes.