*Activities of the Soshisha are represented in black letter
| 1908 | Chisso factory built in Minamata village. |
| 1932 | Chisso begins production of acetaldehyde using mercury catalyst. |
| 1956 | Official confirmation of Minamata disease |
| 1957 | Mutual-aid Association of Minamata Disease Patients and their Families formed. |
| 1959 | "Sympathy Agreement" between Chisso and the victims. |
| 1968 | The Government admits officially that Chisso's organic mercury causes Minamata disease. |
| 1969 | Lawsuit filed in Minamata disease trial ("first trial"). |
| 1971 | Direct negotiations with Chisso begins staging a sit-in in front of the head office in Tokyo. |
| 1972 | Plaintiff patients express the desire for a support center for patients and their families. |
| Calls for a Minamata Disease Center made at the First United Nations Conference on the Human Environment (Stockholm). | |
| Donations solicited nationwide. | |
| 1973 | Victims win suit against Chisso. |
| Compensation Agreement with Chisso by both trial group and direct negotiations group; applied to all certified patients. | |
| 1974 | Net dividing Minamata Bay from the open sea set up. |
| Minamata Disease Center completed. Named "Soshisha" (meaning "mutual consideration"). | |
| Minamata Disease Certification Applicants' Council formed. | |
| Mushroom factory constructed. Work by patients and others begins there (-1983). | |
| Collection and analysis of mercury-laden sludge, fish, and shellfish from Minamata Bay. | |
| 1975 | Exchange of visits with leaders of Canadian Indian Minamata Disease patient group. |
| "Fake patient comment" by Sugimura and others, members of Kumamoto Prefectural Assembly. | |
| 1977 | Beginning of activities as base for uncertified patients' movement. |
| Minamata Experiential School opened (study and exchanges regarding Minamata disease; now the "Gonzui School"). | |
| Beginning of sales of low-pesticide citrus fruit grown by Minamata disease patients. | |
| 1978 | Governmental notification narrowing the certification criteria. |
| Government begins providing financial support for Chisso by issuing prefectural bonds so that compensation payments continued. | |
| 1979 | "Detsuki Health Center" established. Acupuncture, moxibustion, and massage treatments provided. (Separated from Soshisha in 1986) |
| 1980 | Third lawsuit filed. |
| 1982 | Minamata Life School opened (free school; study of Minamata disease and organic farming, -1992). |
| Minamata disease patients moved to the Osaka district file a suit. | |
| 1983 | Document center completed. Documents related to Minamata disease collected, organized, displayed, loaned, published, etc. |
| 1986 | Survey of distribution of plants and animals around Minamata Bay shoreline |
| The 30th anniversary of the official confirmation of Minamata disease. Asian People's Convention was held. | |
| 1988 | Minamata Disease Museum established. |
| 1989 | All directors of the Soshisha resign owing to a matter of sales of citrus fruits. |
| Minamata Disease Patients Alliance formed. | |
| 1990 | Traveling Exhibition of Minamata Disease Museum held at various places in Japan. (-1994) |
| "Environmental restoration of Minamata Bay" (dredging and reclamation of mercury-laden sludge) finished. | |
| Publication of newsletter begins. | |
| The Environmental Creation Development Project in Minamata begins. (-1999) | |
| 1993 | Illustrated Minamata Disease published (bilingual, in both Japanese and English). |
| 1994 | Citizens' Gatherings to Consider the Recovery of Minamata ("Sorosoro moyainaoshi ba hajimen ba") begin to be held. |
| 1995 | Cabinet approves "the Final Settlement of Minamata disease." |
| 1996 | The 40th anniversary of the official confirmation of Minamata disease. MINAMATA Tokyo Exhibition held. |
| 1997 | Net dividing Minamata Bay removed. |
| 1998 | Indonesian and Tagalog editions of Illustrated Minamata Disease published. |
| 2000 | Financial support for Chisso at Government expense begins. |
| 2001 | Osaka High Court find national and prefectural governments guilty. |
| Events in conjunction with International Conference on Mercury as a Global Pollutant held. | |
| 2002 | Attendance at the World Summit on Sustainable Development in Johannesburg. |