Successfully complete the indicated task to unlock the corresponding scenario:

Battle Of Nagashino: Successfully complete the "1582" scenario in Unification mode. 
Incident In Osaka: Successfully complete a "Unification" scenario with a "Regent" rank.
Onin Legacy: Successfully complete a "Unification" scenario with a "Shogun" rank. 
Ten Years After: Successfully complete the "1570" scenario in Unification mode. 
The Final Battle: Successfully complete a "Unification" scenario with all researchable 
                  Zechnologies completed. 
To Declare War: Successfully complete a "Unification" scenario while playing as the 
                Oda Clan, and view five Nobunaga-related events.