I recently found a documentary clip on the Battle of Okehazama that was aired back in November of 2000. The show was hosted by Matsudaira Sadatomo and the Sengoku historian Owada Tetsuo appeared as a special guest. The documentary is in Japanese.
Here are the topics that were discussed:
- The bad weather (rain/thunderstorm)
- Yanada Masatsuna's intelligence
- Nobunaga's youth
- Geography of the Okehazama area
- The timing was critical when Nobunaga received the intelligence
- Usage of the Shincho-Ko ki
I do own a copy of the Okehazama special that was aired back in 2007. Both documentaries are very good and useful to understand the battle of Okehazama.
Nobunaga no tame!