This image was adapted from a picture posted to publicdomainq.net. All of the images on this site are in the public domain i.e. CC0. This site is only in Japanese but can be easily navigated with Google Translate. There are *many* cutesy vector graphics images on this site.
男老師（＃2）
blackboard、chalkboard、class、classroom、coat、doctor、education、eyeglasses、instruction、instructor、lab、labcoat、lecturer、male、man、pointer、pointing、professor、scientist、stick、teacher、tie
黑板、黑板、類、課堂、塗層、醫生、教育、眼鏡、指令、講師、實驗室、實驗工作服、講師、男、人、指針、指點、教授、科學家、棒、老師、貼
資料來源：openclipart ( https://openclipart.org/ )