Lonely thirty-seven-year-old Satoru Mikami is stuck in a dead-end job, unhappy with his mundane life, but after dying at the hands of a robber, he awakens to a fresh start in a fantasy realm...as a slime monster! As he acclimates to his goopy new existence, his exploits with the other monsters set off a chain of events that will change his new world forever!
Shizu dreams about her past; about when she was summoned by Leon and he had Ifrit possess her. She recalls the anguish she felt when the Ifrit residing inside her killed a new friend she made and little monster they named together after she and Leon were considered enemies by the monster. Later, just as Shizu prepares to leave Rimuru's village with the adventurers, Ifrit once again takes control of her and unleashes his flames upon the village. With his water attacks proving ineffective, Rimuru copies Elen's ice magic spell to take care of Ifrit's minions. Discovering that he is immune to fire attacks, Rimuru swallows Ifrit, separating him from Shizu in the process. Now Ifrit lies trapped in Rimuru's stomach where he encounters the monstrous being known as Veldora Tempest.