Miyoshi is a sapphire slime which has a transparent body that is blue in color, resembling water. Having no fixed shape, it can take any shape or form it desires, such as sprouting tentacles or forming arms.
Miyoshi seems content with his master, able to understand his needs.
Miyoshi is a Sapphire Slime summoned by Ainz to serve as his bathing attendant.
The Two Leaders Arc
- Main article: The Two Leaders Arc
Miyoshi made his appearance washing Ainz's skeleton body as it was more effective than with rinsing with water.
The Pleiades Day Arc
- Main article: The Pleiades Day Arc
Sometime after the annexation of E-Rantel, Miyoshi was kidnapped by Solution out of jealousy for his duty in washing Ainz's body. After apologizing to Ainz, Solution extracted Miyoshi from herself. Ainz ordered her to return the slime back where she found him after he was washed in water.
|NOTICE: The following section and subsequent subsections are considered NON-CANON to the Overlord Light Novels.|
Mass for the Dead Arc
- Main article: Mass for the Dead Arc
Miyoshi was summoned by Momonga from a book in Ashurbanipal to serve as his bathing attendant. His existence was found out by Solution who grew jealous of his position. The Pleiades maid then proceeded to kidnap the slime and hide him in her body. The maid hoped that with Miyoshi gone, Momonga would call for her to help clean him. However the disappearance of Miyoshi caused only Momonga to place Nazarick on red alert as it was believed an intruder had entered the tomb and caused the disappearance. As things were about to spiral out of control, Solution confessed her crime to Yuri and Momonga. After she revealed her intentions and freed Miyoshi, Momonga chose not to punish her as the situation was already embarrassing 
Solution though still coveted Miyoshi position as Momonga's bathing attendant and later after the facilities in Spa Resort Nazarick were restored requested a chance to prove that she was a better attendant than the Sapphire Slime. It led to a competition that most of the females NPCs participant where the right to compete with Miyoshi was the prize. However Momonga acting as the final competition defeated all the contenders thus allowing Miyoshi to go unopposed. Miyohsi seeing Solution's disappointment of losing an opportunity to serve Momonga, allowed the women to see his work when he cleaned Momonga's bones. His skill is enough to convince Solution to bury her grudge with the slime and admit he was the slime for the job.
Abilities and Powers
As a dangerous breed of slime, Miyoshi could easily melt flesh with acid and is strong enough to bend metal bars. However, due to his weak level, he is only strong enough to clean the bones on Ainz's body.
Miyoshi is Ainz's personal bathing assistant. Ainz uses Miyoshi to clean his body since as a slime, Miyoshi can reach all parts of his skeletal body. Ainz thinks that the idea of using slimes to bathe is by far his best idea since coming over to the New World.
Miyoshi found himself the target of jealousy by the Predator Slime after she learned he was responsible for cleaning Ainz. Once she learned this, she kidnapped him, hiding the slime inside herself.
- Ainz uses Miyoshi as his personal bathing assistant as it is difficult for him to wash his skeletal body clean entirely.
- Slimeko joking wonders if she could play as Miyoshi in Mass for the Dead.