Tuuli (トゥーリ Tuuri) is Main's older sister.
Tuuli has blue-green hair, a mix of her mother Eva's green and her father Gunther's blue. After Myne wakes up, she has it tied up in a dirty braid. In the light novel and anime, Tuuli's bangs are shown to be centered, but in the manga, they are brushed to the right. She has blue eyes.
For her baptism, Tuuli's hair was cleaned and tied half-up. Tuuli is much cleaner than her age cohort due to Myne's insistence on frequent washing and use of shampoo.
Tuuli was born in the summer before Myne to her soldier father, Gunther and her dyer mother Eva. Prior to Urano being reincarnated as Myne, Tuuli was often forced to take care of her sickly sister while her parents worked. This caused her to mature quicker and develop a strong sense of responsibility.
After Urano's reincarnation as Myne, Tuuli was able to gain a bit more free time and independence as Myne started learning to take care of herself. Prior to her Baptism, Tuuli spent her days helping her mother Eva around the house and traveling to the forest to forage for food and firewood.
The summer Tuuli turned 7, she and all of the other children turning 7 that season traveled to the Temple for their Baptism. Tuuli was registered as a citizen of Ehrenfest during that time.
Since a child needs a referral from a parent or family member to become an apprentice somewhere, children generally wind up in jobs similar to their parents. This was also the case for Tuuli as she was able to secure an apprenticeship as a seamstress through her mother's referral.
Tuuli is practical, caring, and responsible young girl. From a young age she was forced to look after her sickly sister Myne. Myne frequently refers to her sister as an "angel" due to her sweet demeanor. Others in their neighborhood trust Tuuli to look after younger children when they make trips into the nearby forest for supplies.
Tuuli for all her responsibility is still a child at heart. She is not immune to bouts of anger and frustration towards Myne's more eccentric behaviors. Tuuli cares a great deal about her family and cried at the thought of losing Myne to her sickness.
Tuuli often acts as a foil to Myne. Where Tuuli is practical and mature, Myne is a daydreamer and self-interested. While Tuuli is considered the model child of the neighborhood, Myne is considered very weird and scary.
- Tuuli is one year older than Myne, but due to the difference in their health look to be about 3-4 years apart in age.
- Tuuli greatly admires Corina, Benno's younger sister and Otto's wife. Corina is a highly influential seamstress and Tuuli wishes to apprentice under her after her current apprentice contract runs out.
- It is hinted that Tuuli might have a small crush on Lutz's older brother Ralph.