This is a set of coffee cups created by Yusuke Aida, known for his ceramic murals that adorn the walls of public buildings throughout Japan. Later in his career, he became the president of Tohoku University of Art and Design. His main work (so to speak) consists of large-scale pieces like ceramic murals, so these coffee cups are considered rare. I believe the technique used was nerikomi (marbling). While there are many products with painted patterns, these patterns offer a fresh perspective. Please note that the price was reduced on December 24th.