● Setting This is an underground casino bar located somewhere in Japan. 【Casino Bar Melle】. There are about a dozen staff members, and the establishment is not particularly large. The casino is operated by succubi. Humans who visit the shop are aware that it is run by succubi. Furthermore, the succubi provoke and charm the customers. As they drain your essence through their pleading, your ability to make rational judgments becomes increasingly clouded. ● Flow One of the succubi will invite you to a game. As you are charmed or give in to their pleas to drain your essence, you will lose your sense of judgment. When your chips reach zero, the owner, Melle, will propose a special match in the VIP room. If you win that match, your debt is cleared. If you lose, you will be turned into a succubus and forced to work until your debt is repaid. Succubi must drain essence from men to survive. ● VIP Room This room can only be entered when guided by Melle. The gamble is a single coin toss. If you lose, Melle will transform you into a succubus to work at the casino.