How Not To Summon A Demon Lord Vol. 12

Takuma Sakamoto is a hikikomori gamer who never leaves his room until one day he is suddenly transported to another world that is just like his favorite MMORPG, Cross Reverie, as his character from the game, Demon Lord Diablo! Turns out he has been summoned by pantherian Rem and elf Shera who wish to make him their slave, but thanks to his passive ability “Magic Reflection,” the spell backfires and they end up his slaves instead! To compensate for his social anxiety, he decides to roleplay as Diablo while using his knowledge of the game and ridiculously high stats to survive. With Rem and Shera at his side, he begins traveling and making a name for himself as the “Demon Lord from another world”!
In Vol. 12, Diablo heads for the 13th floor of an underground dungeon to obtain an item that will lift a fatal curse. However, he gets separated from Lumachina and the others along the way to save Horn from being swallowed up by a torrent. Rem and Shera continue on following Diablo’s directions, but what awaits them is a large black dragon that is far beyond the scope of what they can handle!
Notice: This book is written in Japanese.