You might be interested in threads from the FAQ section on "Seppuku aka Ritual Suicide in Japan":

History

-o- How common was ritualistic suicide in Japanese society? - 8 comments, over 1 year old.

• This thread goes into the origins, evolution, popularization, and use cases of Seppuku in pre-modern Japan.

-o- How common was seppuku (Japanese ritual suicide)? - 5 comments, over 8 months old.

• This thread gives a primer on the issue from the Sengoku Era into its idealization and use in Imperial Japan while dealing with many myths that surround the matter.

Other Threads

-o- How often would seppuku occur? - 5 comments, over 1 year old.

• The last top level comment talks about the factors involved in deciding upon Seppuku that are broadly applicable in pre-modern Japan.

-o- Why did Emperor Hirohito not commit Seppuku? - 29 comments, over 10 months old.

• This thread covers the prevalence of Seppuku during the war as well as the Emperor's perceived and actual responsibility for the war.

-o- What would happen if a samurai incorrectly committed seppuku and didn't die? - 10 comments, over 1 year old.

• The commenters here discuss the mechanics of the ritual.

-Followup Questions

If, after looking through the above threads, there are major questions that have been left unanswered or specific topics given insufficient detail, feel free to ask followup questions. Liberal quoting from these threads are encouraged to both allow for clearer answers and to prevent users from wasting time repeating points already addressed.

The following users are flaired on the topic and/or have answered questions on it in the past, and would likely be able to answer these followup questions:

-o- /u/AsiaExpert

-o- /u/churakaagii

-o- /u/ParkSungJun