Shouseki

Shoseki (笙関, Shoseki) is the apprentice of tool maker Iou.

He is an apprentice of Iou, and is helping him in his tool-making job. He often complains about hard work. One time he mistakenly sold Gameru and Kusune two ninja tools Iou created: Tsuru-Kame and Dako, to increase their budget.

(source: Narutopedia)