Eyewitness Reports of Isshi and Events
| September 3, 1978 | A group of 20 fifth grade elementary school students in the lakeside Ikezaki neighborhood heard a mysterious splashing sound coming from approximately 300 meters offshore. ① |
| October 1978 | The Ibusuki City Tourism Association Response Committee was established. |
| November 1978 | An unmanned observation station with a surveillance camera was installed. |
| December 16, 1978 | On an otherwise calm day, the center of Lake Ikeda suddenly became agitated and a white creature surfaced. ② |
| August 25, 1990 | A creature with two clear humps was spotted swimming approximately 200 to 300 meters offshore, moving toward Mt. Kaimon. The two humps rising out of the water were spaced roughly 4 to 5 meters apart. Alternatively, the sighting may have been a group of two or more dolphins. ③ |
| December 21, 1990 | A creature was spotted on the lake. At first believed to be a shorebird, when the creature did not fly off, it was suspected to be either a giant eel or Isshi. ④ |
| February 2, 1991 | The Isshi Task Force was established. |
| February 7, 1991 | A creature was spotted from Yasuragi Park. The right side of the creature resembled a head, while the left side appeared to be a tail. ⑤ |
| February 9, 1991 | A creature was spotted swimming several hundred meters offshore from the lakeside near Yasuragi Park. The creature traveled from north to south, surfacing and diving as it swam. ⑥ |
| February 16, 1991 | A 5-meter form was sighted in the center of Lake Ikeda. ⑦ |
| February 27, 1991 | The Isshi Countermeasures Council was established. |
| March 16, 1991 | The “Let’s Play with Isshi-Kun” event was held from March 16 to May 12, attracting 26,432 visitors. In the event space, participants drew pictures of what they imagined Isshi might look like, with a total of 2,670 pictures submitted. |
| March 16, 1991 | Isshi Special Search Party: A raft made of 40 tatami mats and 40 metal barrels was built and used to monitor the lakeshore for nine consecutive days. |
| March 19, 1991 | A black creature suddenly appeared 200 meters offshore. It resembled a parent-and-child dolphin pair playfully surfacing and diving. ⑧ |
| June 1991 | “Emergency Report: Sightings of the Mysterious Isshi!” was published in Japanese by the Keibunsha publishing company |
Note: This is a selection of sightings and should not be considered a comprehensive list.