I wasen't sure where to put this, but I've completley forgotten about Otacon's family life.

Wasen't his father a scientific engineer like his son? I can't remember whether this was mentioned or not..I can't remember whether Otacon said any of his parents were alive either.

If he has been mentioned and is still alive, is it possible he might play a small role in MGS4?

He did mention his grandfather and father in MGS1, but didn't say anything about either of them being alive or dead.

I don't see how they can play a role in MGS4, or if there is any point to it. I believe they're just a reference to Otacon's dark history of nuke involvement, also showing how Otacon himself has made the same mistake.

But it'd just be the kind of thing we woulden't expect right? Maybe one of those slightly shocking but not mindblowing twists Kojima likes before he truely unloads the big payload on us.

Don't get me wrong, I'm not basing this as a theory and i'm not saying it's going to happen..I just think maybe it's possible.

Didn't Otacon's father kill himself because of the affair Otacon had with his step-mother?

Or was that the step-mother who killer herself?

As for his grandfather, I doubt he is "still" alive. He was involved in the Manhattan Project and was one of the project leaders, which would mean he was at youngest early 30's in 1945, which means he would be 100 plus by 2014.

Holy shit, how could I forget? Otacon's father took his own life because of the affair. Right you are.

Oh damn. That blows this topic out of the water then.

I doubt this will play a role in MGS4 but if I'm correct Otacon mentions about his whole family in MGS2 some videos after Emma's death and that they died.

EDIT: Now I've seen the above posts... I'm too late, everything is answered.

Funny you should say water - didn't Otacon's father kill himself by drowning himself in a swimming pool and made it look like an accident?

And do you think there is any chance Otacon's Grandfather could have played a part in the creation of the Shagohod or RAXA?

Well the guy in the photo in Granin's office looks a lot like Otacon and is the one mentioned to have the theory on putting a tank on legs along with Granin...

Although wasn't RAXA a Russian project? (Given that the San Hieronymo Province was Russian held)

This guy in the picture is very likely Otacons grandfather or father. Granin also says he is going to send the Metal Gear Rex plans to his "American friend". Otacon made Metal Gear Rex, so.. He probably got the plans from his father or grandfather.

It is actually confirmed (as if we needed it) that Granin's American friend is Otacon's father - which only furthers the Emmerich's dark history surrounding nuclear weapons.

Otacon's Grandfather: Participated in the Manhattan Project.
Otacon's Father: Researcher in the early Metal Gear projects.
Otacon: Metal Gear REX Project-Leader.
Emma: Developed the Arsenal Gear A.I., GW.

Pretty damn crazy...

One of them were born on the same day as Hiroshima.

No wonder why he wants to end this battle forever (along with Snake of course).
With that kind of history and without being able to escape his past the only good thing he left to do is hope and help/participate for a better future...

Nice genealogical tree. All weapons scientists and similar stuff to this. Only Emma was taking her own path from the start. A good path.

How old was Otacon when his dad commited suicide. His step-mom must have been pretty desperate.

We don't know the exact age but we do know that he was still going to school.
Probably between 14 and 17 years old because that time Emma was also months old.