To start this quest, speak to your siblings during the prologue and agree to help them. You'll find them near your house right after you step outside during the "Withering Away" quest.
Time Segments: 1 - 2
Dad told Yanna and the kids to go catch some trout. Maybe I should help them out? Yanna hates baiting the hooks.

1. Walk your siblings to the river (1 Time Segment)
I agreed to go fishing with my siblings. First, we need to get down to the river.
Run with your siblings toward the river. At one point, the youngest will start whining, and you must choose whether to play with them - which will cost an extra unit of time - or tell them to stop complaining.

1.1. Catch Mirto & Lunka (1 Time Segment)
I need to tag Mirto & Lunka.
If you decide to play tag with the kids, simply run up to them and press the appropriate key / button when the talk prompt appears.

1.2. Look for the fishing rods using Focus Mode
Dad said he hid the rods in the reeds by the river. I've got to find them.
Use Focus Mode to locate the fishing rods hidden in the nearby bushes. Approach them and pick them up.

1.3. Set up the fishing rods by the river
The kids won't have the patience to hold the rods - so I'd better set them up by the river.
Set all four fishing rods along the riverbank at the locations marked by small piles of stones.

1.4. Bait the hooks with worms
Before we can start fishing, I need to bait the hooks.
Simply approach one of the fishing rods and try to bait it. This will trigger a cutscene where Coen shows the kids how to bait a hook. Your dialogue choices don't make much of a difference.

2. (Optional) Defeat the soldier
I have to defend my siblings.
3. Endings
1. Fishing can be a calming experience - but not this time. We were accosted by Brencis's men - and it could've ended badly, were it not for the uriash who led them. Funny, I thought they were mindless beasts...
Reward: 250XP
2. I didn't have the time to see this through - there's only so much one can fit in a day.