You choose how many targets the chaos ability has and how the counters are distributed as you put the ability onto the stack. Each target must receive at least one counter.

If some of the creatures are illegal targets as the chaos ability tries to resolve, the original distribution of counters still applies and the counters that would have been put on the illegal targets are lost. They won’t be put instead on a legal target.

Towashi : règles, fonctionnement et interactions (MTG)

Towashi is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Modified creatures you control have trample and "Whenever this creature deals combat damage to a player or planeswalker, draw a card." (Equipment, Auras you control, and counters are modifications.) Whenever chaos ensues, distribute three +1/+1 counters among one, two, or three target creatures you control.

How it works : Towashi

Original English text — Wizards of the Coast / Scryfall

#1April 14, 2023· Wizards of the Coast
You choose how many targets the chaos ability has and how the counters are distributed as you put the ability onto the stack. Each target must receive at least one counter.
No other card is named in this ruling.
#2April 14, 2023· Wizards of the Coast
If some of the creatures are illegal targets as the chaos ability tries to resolve, the original distribution of counters still applies and the counters that would have been put on the illegal targets are lost. They won’t be put instead on a legal target.
No other card is named in this ruling.