CEDEC 2021 is a professional business conference aimed at computer game developers, engineers, and programmers. It has been held since 2009. In previous years, the event has been held exclusively on-site, with company booths, lectures, and sessions. The previous conference, in 2020, was held online as a result of the coronavirus pandemic. Preparations for the 2021 conference were also made with consideration of the pandemic. The conference, which took place in August, was held during a state of emergency. Despite this, speakers were able to gather at the venue to give their lectures. Some of the speakers who had planned to come to Yokohama to present were unable to do so due to the state of emergency, and, as a result, some last-minute changes were required. However, speakers who were unable to travel to the venue were able to deliver their speeches from their own computers or devices or by streaming pre-recorded video. This was possible because the conference had been planned to be held online. Special sessions called “Ask the Speaker” were organized to stand in for business card exchanges and question periods that are carried out at on-site events.