Our young developer has also failed multiple times.
Horibe, a young developer who had been training in the engineering department, was also one of the many developers faced with this tough challenge. Through experiments, he knew that the hair had a tendency of collecting in the center and the ends of the brush. Using the discovery as a hint, he tried changing the length of the bristles and altering the airflow, but none of the changes was successful in maintaining its original cleaning function, making the development come to a halt.