Mikami Satoru, a businessman, is stabbed by a criminal on the street and killed. When he regains consciousness in the darkness, he finds that he's been reincarnated as a slime! With nothing better to do, he spends his time devouring all the rare herbs and precious ores he comes across. As he does, he encounters the Storm Dragon Veldora, who was sealed in this cave 300 years ago by a hero's "Unlimited Imprisonment" skill. He's frightened at first, but as they talk, he becomes friends with the long-isolated Veldora.
Yes. You see, I was sealed 
here 300 years ago.
نعم. في الواقع، خُتم عليّ هنا منذ 300 عام
Ja. Um ehrlich zu sein,
Sí. Llevo 300 años sellado aquí.
Sí. Llevo 300 años sellado aquí.
Oui.
Sì.
Sim. Na verdade, eu fui
selado aqui há 300 anos.
Угу, понимаешь,
меня тут триста лет назад запечатали…