MTCA workshop for accelerator and physics in Japan 2021 was held from October 26-28 2021 in a virtual format. The goal of this workshop is to boost the application of MTCA in Japan by exchanging the information and experiences. The first day was dedicated for the tutorial session in Japanese and the other two days consisted of oral presentations. The workshop was very successful with more than 120 registered participants. The summary of the workshop and outlook are presented.