The following is the list of characters from That Time I Got Reincarnated as a Slime.
Main characters
Rimuru Tempest's background story begins in Japan, where she was originally a human named Satoru Mikami. One day, while walking home from work, he is stabbed and killed by a criminal. However, he is reincarnated into a fantasy world as a slime monster with unique abilities. He is actually genderless, being considered as both a male and a female. As a slime, Rimuru initially struggles to survive in this new world, but soon discovers that he has the power to absorb and mimic the abilities of any creature he consumes, eventually gaining a nonbinary human form. This allows him to gain new skills and become stronger, even though slimes are considered to be weak monsters. Rimuru eventually meets and befriends different monster races quickly gaining a reputation as a powerful and benevolent leader who strives to build a peaceful society for all races. He then establishes a nation called Jura Tempest Federation and becomes its ruler, promoting equality and justice among all its inhabitants. He also forms alliances with other powerful beings, including the Demon Lord Milim Nava "Destroyer" and the "Storm Dragon" Veldora Tempest. Throughout his journey, Rimuru learns about the politics, conflicts of the fantasy world, and becomes a respected leader who is known for his wisdom, kindness, and strategic thinking. Despite facing many challenges and enemies, Rimuru remains determined to protect his friends and allies while achieving his goals. /
Great Sage is one of Rimuru Tempest's most powerful abilities in the series. It is a "Unique Skill," which means it is a unique ability that Rimuru gained when she was first reincarnated as a slime. Great Sage is a type of artificial intelligence that exists within Rimuru's mind, and it serves as her personal advisor and assistant. Whenever Rimuru faces a problem or needs information, Great Sage is able to analyze the situation and provide suggestions and solutions. It has vast knowledge and expertise in various fields, including science, magic, history, and more. It also has the ability to communicate with Rimuru through telepathy, making it a valuable tool for him. This feature was possible because of a partition of the voice from "Words of the World" also known as "Voice of the world" upon Rimuru's reincarnation to help her. Great Sage's intelligence and analytical abilities are almost unparalleled, and it is able to perform complex calculations and simulations in seconds. It also has a vast database of information, which it can access at any time to provide Rimuru with the answers she needs. In addition, Great Sage has a wide range of other abilities, such as being able to manage Rimuru's skills and abilities, predict future events, and provide suggestions for strategic planning.
One of the four original True Dragons, the "Storm Dragon", Veldora is a powerful dragon classified as a "Catastrophe-level" threat who was sealed away by a "Hero" in a cave for 300 years. When Veldora meets Rimuru, he was impressed by Rimuru's intelligence and confidence, especially being that he was a slime one of the lowest if not the lowest of the monster races the two then formed a strong bond giving each other names. Veldora then teaches him about the world and helps him to improve his skills and abilities. In turn, Rimuru helped Veldora by providing him with companionship and freeing him from the "Infinite Prison". Throughout the series, Rimuru and Veldora work together to achieve their goals and protect their friends. Veldora also provides Rimuru with valuable advice and assistance, using his immense power to aid him in battles against powerful enemies. Their relationship is a testament to the power of friendship and loyalty, and their bond remains strong even when they are separated for prolonged periods of time. Overall, Rimuru and Veldora's relationship is one of the major highlights of the series. He is soon given a human body and is also revealed to be the uncle of the Demon Lord Milim Nava.
Shizue, also known by her nickname , is a Japanese girl who was summoned into this world, during the Bombing of Tokyo. Her summoning was considered a failure, and she was abandoned after having a fire spirit, Ifrit, bound to her body. Soon after, she gained the title "Conqueror of Flames". Shizu is actually of elderly age, but has not outwardly aged past her prime thanks to Ifrit's possession. She figures out that Rimuru was also once from Japan and in their short time together, they become good friends. Before passing away, she requested her body be devoured by Rimuru, giving her a human form. Rimuru also wears her mask as a keepsake.