Servant of the People is Kenji Tale 1 of 3, an Act 1 side tale at Aoi Village in Tsutsu. You find Kenji claiming to protect farmers' food from the Mongols, which of course goes wrong. It needs The Broken Blacksmith done and rewards the Charm of Well-Being I and 10 Linen.
Part 1 of 3 in Kenji's Tales
Part 1 of 66 in Tales of Tsushima
A farm in Tsutsu looks like it has had trouble, so you stop to check. Kenji is there, saying he is helping the farmers keep their food away from the Mongols. Jin suggests an ambush, and Kenji says it will not be that simple. Follow him, talk it through, then fight the Mongols and speak to the captive they took.
Talk to Kenji. Go with him and talk again. Beat the Mongols. Talk to the freed captive.
Kenji had sold the Mongol raiders fake supplies so the villagers could keep their real food, and took a cut on the side. The Mongols worked it out and took the real food, hostages and Kenji's horse, Miko. Jin gets into their camp hidden in one of the barrels and wipes them out. The freed villagers are not happy with Kenji.
Do this one before Act 2 starts so it does not get locked behind liberating Aoi Village. The Linen reward is handy for early armor upgrades.
Nattou and the Sake Seller
Nattou and the Sake Seller is Kenji Tale 2 of 3, an Act 2 side tale south of the Ruins of Old Yarikawa in Akashima. Kenji says an empty Mongol camp is ripe for looting, and it is not empty for long. It rewards the Charm of Advantage.
The Delicate Art of Negotiation
The Delicate Art of Negotiation is Kenji Tale 3 of 3, the last of his tales, set at Umugi Cove in Act 2. You act as Kenji's hidden bodyguard while he meets a criminal he owes money to. It rewards the Charm of Broken Barriers and 6 Leather.
A Place to Call Home
A Place to Call Home is a short Ariake side tale where a panicked man asks you to retake his house from the Mongols. You clear the house, then follow clues to learn what became of his family, and earn a Charm of Well-Being I.
The Unbreakable Gosaku
The Unbreakable Gosaku is a Mythic Tale that starts in Akashima Village, Toyotama. You free six farmsteads to collect six keys, then open a hill in the Old Togo Rice Fields to claim Gosaku's Armor, a tanky set built around Staggering enemies.