I've done a lot of boss battles in a lot of games, and one thing I…

When Kojima reread Shibumi in 2006 as part of his research for Metal Gear Solid 4, he was startled by parallels with ideas he had already used: a combat discipline similar to CQC, the heightened threat perception he learned in scout/tracking training, and the merciful murder of a parental figure, which he related to Big Boss and The Boss. His reappraisal led him to recommend the novel to the development team.

“Every game I make, I create thinking it's really, really going to be the last game I create. So I put as much as I can in and make sure I have no regrets.”

“In the beginning, I would say the answer to that is yes. I had very specific people in mind when I created a game, and I had a message that I wanted to pass along. But now my thought process is changing.”

“But it's like when Hayao Miyazaki says he is not going to do more, and then always ends up doing it. I think I am kind of in a similar situation; I have ideas other than Metal Gear, and I want to go on to make other new games, but for political, business or technology reasons, there is always a time when I have to return.”

In a September 2011 essay, Kojima wrote that each time a new Metal Gear came out he declared to the press that it would be the last he would make. He explained that all stories and all creators have an end, and that he wanted to bring his own story to its conclusion before he reached his.