Short answers, pulled from the story.
Oda Nobunaga was a Japanese samurai and daimyo born on the 23rd of June 1534 in Nagoya, Owari Province. He is regarded as the first of the three great unifiers of Japan, alongside Toyotomi Hideyoshi and Tokugawa Ieyasu, and he overthrew the Ashikaga Shogunate in 1573 while consolidating control over most of Honshu by 1580.
Nobunaga died on the 21st of June 1582 during the Honno-ji Incident in Kyoto, when his retainer Akechi Mitsuhide surrounded the Honno-ji temple before dawn. Trapped with only 30 pages, Nobunaga committed seppuku in one of the inner rooms after resistance proved futile.
The Battle of Okehazama took place in June 1560, when Nobunaga attacked the camp of Imagawa Yoshimoto with a force of 2,000-3,000 men against an Imagawa army of 25,000. Nobunaga launched a surprise assault after a thunderstorm, Yoshimoto was killed by two Oda samurai, and the victory dramatically raised Nobunaga's prestige and drew warlords across the region to pledge fealty to him.
Nobunaga abolished barrier posts within his domain to allow free movement of goods, promoted raku-ichi raku-za to break guild monopolies, and enacted the Oda Nobunaga Eiroku 12 Law in 1569, introducing a fixed exchange rate and coin classification that some researchers consider the beginning of early modern monetary policy in Japan. He also widened roads to three and a half meters, built bridges, and developed maritime routes to speed the movement of goods and armies.
Nobunaga recognized the potential of matchlock guns in 1549 and put Hashimoto Ippa in charge of production; by 1550, the Kunitomo Teppoki records that 500 guns had been completed. He fielded firearms for the first time at the Battle of Muraki Castle in 1554 and later established an international supply chain through Portuguese merchants to import potassium nitrate for gunpowder, making sustained large-scale firearms deployment possible.
Tenka Fubu was a personal seal Nobunaga adopted after capturing Inabayama Castle in 1567, which he renamed Gifu. The phrase translates as "All under heaven, spreading military force" or "All the world by force of arms" and functioned as a public declaration of his intent to conquer all of Japan.