The Sickle Upon Sekigahara: Who Is Hideaki?

The main character, in other words the person you will be playing as, in The Sickle Upon Sekigahara is the young medieval warlord Kobayakawa Hideaki. For those who don’t know much about the climactic Battle of Sekigahara in 1600, Hideaki is not a particularly well known figure. So who was he exactly, and why did