Yoshimoto Imagawa was a Japanese warlord that lived during the Warring States era. He is most famous for his defeat at the hands of Nobunaga Oda and his forces that led to his demise at the Battle of Okehazama in 1560. Prior to the battle, he had successfully formed an alliance with the Takeda and Hojo clans, and he chose to march his forces toward Kyoto. His route took him through the province of Owari, which was under Oda rule.
While encamped in a heavy rainstorm, Imagawa's supposed force of 40,000 soldiers (some sources indicate that Imagawa intentionally overstated the size of his army to frighten off opponents) celebrated their recent successes by drinking heavily. Nobunaga took advantage of the lax attitude of the Imagawa soldiers by staging an attack just as the rain cleared. Despite being heavily outnumbered (the Oda forces totaled only 3,000 troops), the ambush was a resounding success and the drunken, frightened Imagawa soldiers were easily routed. In the end, Yoshimoto Imagawa was captured and executed. His defeat is seen by historians as the first major step in Nobunaga's rise to power in the era that followed.
In the Samurai Warriors series, Yoshimoto is depicted as being incredibly naive and childish in accordance with the ease with which the Oda forces historically defeated him. His forces hold very little respect for him, and in some stages in the games will actively turn against him. He is also depicted as having an unusual obsession with playing kemari; a Japanese form of kickball, and he is frequently more focused on his own childish pursuits than on leading his men into battle.