"We are the lightning in the storm"
Lord Kazumasa Sakai (境井 正; Sakai Kazumasa) was Jin Sakai's father and the former Samurai lord of Clan Sakai. He was killed by a bandit as Jin watched, asking for Jin's help. His blade, the Sakai Katana, was passed down to Jin at his funeral by Lord Shimura. The Guiding Wind is a personification of Kazumasa Sakai.
Kazumasa was the head of Clan Sakai, preceding his son, Jin Sakai. He was married to Lord Shimura's younger sister who passed away seven years after the birth of their son. He lived in the Sakai's household in Omi Village, Toyotama region, which also became Jin's childhood home.
After the death of his wife, Kazumasa struggled with parenthood and chose mostly to devote into his duty as Samurai. Among these duties were the violent attempt ordered by the Jito to pacify Iki Island, which at that time was under control of several bands of raiders and pirates. Kazumasa brought young Jin into this invasion, making it among his son's earliest direct involvement in warfare. After series of harsh battles and gruesome conflicts, Kazumasa became known as the Butcher of Iki, tarnishing his clan's reputation in the island even long after his passing. Eventually, Kazumasa and his soldiers were led into an ambush in Senjo Gorge, where Kazumasa was killed with his son witnessing.
Jin was haunted by guilt and regret of his father's demise for years afterward. As a result of this, he refused to wear his father's armor to the Battle of Komoda Beach, instead opting for Clan Shimura's Samurai Armor. After rescuing Lord Shimura from Castle Kaneda, which allowed him to overcome his guilt to a certain extent, Jin was encouraged by his uncle to leave his past behind him, which spurred him to reclaim the armor set in as they push into Toyotama region. At an undetermined time around the Mongol Invasion, Jin would make a return to Iki Island and finally fight for closure in regards of his father's legacy.
Kazumasa's spirit lives on as the Guiding Wind.
- According to Yuriko in The Proud Do Not Endure, Kazumasa was a creative person that might have even been okay with The Ghost, since he 'had imagination'. In addition, he thought of Lord Shimura as too rigid and "willfully blind to possibilities".
- In The Conspirator Tale, it is said by Masako that Lord Shimura hunted down the man who killed Kazumasa and cut off his head. However, as seen in the Iki Island expansion, this appears to have been either a lie by Lord Shimura or an oversight by the developers as several other retcons were made since Iki's release to match the story up with the events of Iki Island.
- Considering that cover-up stories to embellish the fate of prominent members of the 5 great clans of Tsushima do happen in the game ( as with Hironori Nagao), the idea that such story was made up to make it seem that the Sakai clan was avenged is still completely plausible, though not confirmed.
- Shimura's status is determined by the player.