Currently, he’s Venerable Justo (or Justus) Takayama Ukon.
His Christian name was Justo, and Western Christian sources called him “Dom” (Portuguese for lord). Takayama is his family name, and Ukon was his office name that he went by as an adult. Other names are Hikogoro (his baby name, which Japanese back then usually changed upon becoming boys or adults) and Shigetomo (his young man name).
He was a great general, but also waged peace. He loved Japan but died in exile. His life story is full of twists and turns, but he seems to have lived it all with honor and good sense.
The man has his own “Dom Justo Takayama Ukon” TV Tropes page. It’s a good explanation page. Just don’t follow the links if you want to do anything else today.
He has appeared as a character in various anime and manga, including Hyouge Mono (which is about a fellow disciple in the Way of Tea) and The Ambition of Oda Nobunaga (an alternate universe history/time travel anime).
I previously covered Blessed Diego Kagayama Hayato, the faithful samurai retainer who gave pro tips to his executioner; the blind biwa player, Jesuit brother Lourenço Ryousai; and the possible ninja-clan martyrs, Blessed Joannis Hattori Jingoro and Blessed Petrus Hattori.
More stories of the Japanese martyrs. “They were killed and they conquered.”