784. Why are these Katakana seen in a lot more characters? ロ ン ム ヨ シ

Answer:

They are all radicals, or look like one.

ロ  The "Kuchi" radical - mouth

ン  The "Nisui" radical - ice"

ム  The "Mu" radical - private, Katakana Mu

ヨ  The "Keigashira" radical - pig’s head

シ  The "Sanzui" radical - water