Kato Kiyomasa (1562-1611) was a fierce warrior, castle builder, agricultural genius, Toyotomi Hideyoshi's right hand man, devout Buddhist, and all-around badass.
One of Hideyoshi's earliest and most loyal supporters, Kiyomasa first distinguished himself at the Battle of Shizugatake for which he earned 3000 koku and gained renown as one of the "Seven Spears of Shizugatake." In 1592 Kiyomasa led a Japanese invasion of Korea on Hideyoshi's orders, and fought so viciously that he earned the nickname "demon general." Kiyomasa never cared for the the airs and culture that samurai were supposed to affect. "I only love battle," he said, and once famously ordered that any samurai caught dancing in his domains commit seppuku at once.
After Hideyoshi's death Kiyomasa sided with Tokugawa Ieyasu and emerged as one of the heroes of Ieyasu's great victory at Sekigahara, for which Ieyasu awarded him a huge estate worth 540,000 koku and made him governor of Higo province. But Kiyomasa always remained loyal to Hideyoshi's young son Hideyori and hoped that Ieyasu would uphold Hideyoshi's last wish that his son rule when he came of age.
When not wrecking shop on the battlefield, Kiyomasa was a great builder of castles and temples. He rebuilt his own Kumamoto Castle into one of the loveliest in Japan, and planed and constructed a town below it. Kiyomasa devised several ingenious new methods for irrigating his lands, making him very popular with his serfs. A devout adherent of the Nichiren Buddhism sect, Kiyomasa had numerous new shrines and temples built, and vehemently opposed the spread of Christianity in his domains.
In 1611 Kiyomasa arranged a summit between Ieyasu and the last remnants of the Toyotomi clan, in hopes of achieving a reconciliation. Kiyomasa died suddenly while on his way home from the summit, so he never saw his dream fulfilled, but of course Ieyasu never had any intention of letting Hideyori rule.