Tokyo Reports Suicide Wave Before Palace of Emperor
There was a strong relationship between the military and suicide. Even as late as 2008 it is still an issue:
http://news.asiaone.com/News/Latest+News/Asia/Story/A1Story20080328-56769.html
Under pressure, the education ministry in December restored references in history textbooks to note that Okinawans ‘committed group suicides with the involvement by the Japanese military.’
Here is a list of Japanese military suicides.
https://en.wikipedia.org/wiki/Category:Japanese_military_personnel_who_committed_suicide
On 14 August 1945, Anami signed the surrender document with the rest of the cabinet, then attempted suicide by seppuku early the next morning. Failing to conduct the ritual properly he had to be dispatched by his brother-in-law.[dubious – discuss][6] His suicide note read: “I—with my death—humbly apologize to the Emperor for the great crime.”[7] This “cryptic” note is open to multiple interpretations.[8]
Not much reference at the below regarding the Japanese surrender but describes the history and process:
https://en.wikipedia.org/wiki/Seppuku