Since May 2021, the Joho Laboratory has been conducting joint research with Yahoo! JAPAN Research of Yahoo Japan Corporation on the theme of "Improving the Web-based Information Access Environment from the Perspective of Human-Centered Information Retrieval Research”. The government's "Society 5.0" concept aims to create a human-centered society in which "necessary information is available when it is needed," and to realize this goal, it is essential to diversify and upgrade information access technologies that form the basis of web search and information recommendation services. A human-centered society also requires technological development that takes into account fairness, accountability, confidentiality, transparency, and security. With this background, this joint research aims to propose solutions to the various problems derived from existing algorithms from the viewpoint of human-centered information retrieval, by carefully examining the user logs and contents of information access services that are becoming increasingly sophisticated and complex. We are currently focusing on fairness-aware ranking and conversational information retrieval techniques. Students in the joint research project participate in a workshop called Text REtrieval Conference (TREC) organized by the U.S. National Institute of Standards and Technology (NIST). They also submit papers to top conferences in Information Retrieval based on their research findings, gaining valuable experience of collaborating with a leading company in the field.