The River Children is an Act 2 side tale at Old Kanazawa Marsh. A woman named Shino swears a kappa dragged her father away, and you follow the tracks to find out what really took him. It pays a Charm of Bludgeoning.
Part 62 of 66 in Tales of Tsushima
Near Old Kanazawa Marsh you hear a woman crying. That is Shino.
Shino heard screams and splashing by the river and is sure a kappa took her father. Jin suspects a person did it, but goes to look either way. The father made his own flute, which matters later.
Check the docks and the riverbank, then follow the tracks across the river. Examine what you find, look over the riverbank again and keep tracking. Defeat the bandits, search their belongings and talk to Shino.
Her father is dead, killed by bandits. Among their things is his handmade flute, which you return. Shino still thinks only a demon could do this, and Jin explains what desperation does to people. She leaves for Akashima to live with her aunt, where she later trains as a healer.
The Thief
The Thief is Masako Tale 7 of 9, an Act 2 side tale near Kawamata Village in Kushi. You track Mai, a former Adachi servant who looted the estate after the massacre, and recover the stolen heirlooms. It rewards the Charm of Bludgeoning and 2 Silk.
The Laughing Bandits
The Laughing Bandits is an Izuhara side tale that starts with a crying woman in Kechi Fishing Village. You investigate a home, track bandits to the Komoda ruins and clear them out, earning a minor melee charm and 10 linen.
A Debt Repaid
A Debt Repaid is an Act 2 side tale in Kushi, Toyotama, where you help a man named Gomyo take revenge on the bandits who used him. Expect a camp assault and a second wave, and a Charm of Enduring Affliction at the end.
A Final Request
A Final Request is a Toyotama side tale that starts with Straw Hat ronin raiding Lucky Genzo's Inn. You chase the raiders through three camps to find a captured man named Oda, and the reward is a Charm of Dual Destruction II.