That kind [1] of language-script mismatches mainly for humorous purposes actually exists in Korean and is considered a kind of 한본어 (a portmanteau of 한국어 Korean language and 일본어 Japanese language).

[1] In this case, Japanese そうですね "I see" written in Hangul.

Chinese phonology is a bit restrictive but I have great fun written short messages in other languages (Japanese, French, English) with Chinese characters. Of course the number of friends I can do that why is very limited, which in a way makes it is even nicer.

Yea, I do it all the time in Korean when joking about something with friends. 친구들이랑 그렇게 얘기해요