This story takes place before Rimuru's reincarnation. Shizu, also known as the Conqueror of Flames, responds to an urgent request calling her to the Kingdom of Filtwood. When she reaches the castle, many adventurers are already there. What request could have demanded such a huge gathering? It turns out a demon has been revived, and the adventurers have been called to subjugate it. It is said that more than ten of the most skilled adventurers have already been killed by this demon. But there is more to this request than meets the eye...
Rimuru and Black had their 
fateful first encounter.
تحقّق اللّقاء المحتوم الأوّل بين ريمورو وأسود
Rimuru y Kuro llegarían a encontrarse.
Rimuru y Negro llegarían a encontrarse.
si formarono le basi 
per l'incontro di Limur e Nero.
Rimuru e Preto tiveram
seu primeiro encontro fatídico.
сплелись судьбы
слизи Римуру и демона Черноты.