Ryotaro Shimizu received his BE, ME and PhD degrees in Industrial and Management Systems Engineering from Waseda University, Tokyo, Japan in 2017, 2019 and 2023, respectively. From 2019 to 2020, he was a software engineer at DeNA Co., Ltd. Since 2021, he has been a research scientist at ZOZO Research. Since 2023, he has been a visiting research fellow at the Computer Science Department, University of California San Diego. He engages in research to apply machine learning methods to real-world services. He is a member of the IEEE.