Nirasawa was an avid sculptor and model-builder. He has published books of his original-concept character and monster models and illustrations, including work from his "Creature Core" column in Hobby Japan magazine. He had designs and sculpts toys and resin kits for Fewture Models, including their Devilman products as well as figures of his own original characters. On February 2, 2016, he died suddenly due to renal failure. Was an assistant of Makoto Kobayashi.