- 1907
- Yoshimoto's parents immigrate to Hawaii from Yamaguchi, Japan. They work on a plantation.
- 1909
- Yoshimoto is born on 6th June and named Watson Toshinori. The registration of his birth is presented 21 November.
- 1910
- Yoshimoto enters a public school and a Japanese school in Hauula.
- 1924
- His father Yoshinosuke Yoshimoto (43) passes away.
- 1925
- His mother Kou Nagawa Yoshimoto (39) passes away. Yoshimoto leaves school and becomes an apprentice carpenter on a plantation. He becomes a journeyman carpenter and then foreman before leaving the plantation.
- 1930
- Yoshimoto gets marriage to Amy Kimiye Shimaoka. He changes jobs from a carpenter and gets employed in a construction company. A degree of engineering is obtained with a correspondence course.
- 1931
- His first son Watson Jr. is born.
- 1932
- His first daughter Jeannie Vee is born.
- 1933
- His second son Sadao is born but passes away one year after. Yoshimoto begins to hunt in Hawaii.
- 1934
- His second daughter Maxine is born.
- 1940
- Yoshimoto establishes the Oahu Construction Company.
- 1941
- The Japanese attack on Pearl Harbor on 7th December. Yoshimoto abrogates his Japanese nationality. He continues to work on the construction industry and receives orders mainly from American forces.
- 1948
- He gets divorce from Amy.
- 1951
- Yoshimoto gets marriage to Katherine K. Endo. They move to Ahi Place, Honolulu, Hawaii for life.
- 1954
- He assumes the post of the management on the General Constructors Association in Hawaii and becomes to receive large scales and amounts of orders after this.
- 1957
- Yoshimoto travels to Canada for hunting, which is his first time trip to the foreign country. He continues to travel for hunting almost every year since this year to 1995.
- 1958
- He travels to Africa, Lisbon, Rome, Egypt, India, Bangkok, Hong-kong, and some region of Japan where he meets his relatives. After homecoming, he joins some hunting clubs.
- 1960
- Yoshimoto hunts and gathers the specimens collection of African animals for the order from the museum of San Antonio, Texas. He begins to hunt for taxidermy at some museum’s requests.
- 1963
- Yoshimoto donates a reindeer skull to National Museum of Nature and Science, Tokyo, Japan.
- 1965
- Yoshimoto begins to work on the bowling business parallel with the construction industry.
- 1972
- His taxidermy collections are donated to Bernice Pauahi Bishop Museum, Hawaii, and on display for public.
- 1976
- Yoshimoto is commended to “Man of the year” for contributions to wildlife preservation and his taxidermies of quality from Safari Club International (SCI).
- 1977
- The display of Yoshimoto’s taxidermy is ended in Bernice Pauahi Bishop Museum for remodeling. After this event, he buys back the taxidermies by degrees.
- 1978
- W. T. Yoshimoto Foundation is established for wildlife preservation. Yoshimoto becomes the president of SCI, Hawaii to 1981.
- 1980
- Yoshimoto is award the Wetherby Big Game Trophy, which is called the Oscar Awards for hunters, by Wetherby Foundation International for contributions to wildlife preservation, his taxidermies of quality and education for young people.
- 1986
- He begins to display his taxidermy collection for public at his office and home personally.
- 1987
- Oahu Construction Company is introduced as one of the top 25 companies by a business paper; Building Industry Digest.
- 1988
- Oahu Construction Company is chosen as one of the most succeeded company in Hawaii by a business paper; Hawaii Business.
- 1992
- A private museum “Wild Museum” is open. The museum has been remodeled by a bowling alley and exhibits his taxidermy collection bought back from Bernice Pauahi Bishop Museum. He retires from the construction industry.
- 1995
- Yoshimoto’s final hunting trip, to Spain and Kazakhstan, is conducted.
- 1997
- He decides to donate his collection for National Museum of Nature and Science, Tokyo.
- 1998
- The collection moves to National Museum of Nature and Science, Tokyo. The special exhibition for the Yoshimoto Collection is held. Mr. and Mrs. Yoshimoto come to Japan.
- 1999
- Yoshimoto establishes a scholarship for students studying wildlife preservation in The University of Hawaii.
- 2004
- Yoshimoto passes away.
