| November 2011 | Established Meiseikai Medical Corporation Higashi-Shinjuku Clinic (medical facility with beds; 18 beds) |
|---|---|
| October 2020 | Transferred all equity interests in the clinic ahead of a merger with Keikokai Medical Corporation. Became a Keikokai Group medical institution. |
| August 2021 | Medical corporation merger approved. |
| December 2021 | Merged with Keikokai Medical Corporation and established Keikokai Medical Corporation Higashi-Shinjuku Clinic. |
| April 2022 | Began providing outpatient care. |
