Tartah

タータ

Tartah is a young boy who assists his grandfather, Mr. Nolnoa, in running the magic supply shop The Starry Sword. Although he descends from a line of witches and is not an Outsider, Tartah suffers from a disease called "Silverwash," which causes everything he sees to have a silvery sheen. This condition prevents him from perceiving colors correctly, so he has not received training in the use of magic.
Tartah is a focused young boy who wishes to help the people around him. Because of his Silverwash, he has not undergone proper training to become a witch, despite being born with the ability. Consequently, he can become quickly annoyed when people fail to understand his circumstances, and he has struggled with how his illness bars him from becoming a witch. Tartah can be incredibly motivated when he wants to help someone, as he was with Coco when she was sick.

Spoiler

Initially, Tartah did not take incredibly kindly to Coco. Coco was unaware that he was afflicted with Silverwash and thus asked him questions about colors, to which he reacted with incredible frustration and snapped at her.
However, when Coco becomes sick, Tartah returns to her sick room to look for his hat and stays to help her. She then helps him by devising a spell to help him see the original form of certain medicines so he could find what would help her. Through this experience, he develops a greater appreciation for Coco and becomes friends with her, promising to make a special Ink Wand just for her and to use his own magic to travel and bring it to her.
Tartah and his grandfather's cloaks are short and light - a type preferred by stationers to avoid getting dirty from preparing wands and ink.