As interjections the difference between mwah and chu

is that mwah is making the sound of a kiss; the sound used to indicate sending a kiss through the air; Frequently used in email, chat and text messages to indicate sending a kiss to someone while chu is the sound of a kiss.

As a noun mwah

is the hallmark sound of a fretless bass guitar played with a certain technique, where treble frequencies increase gradually after the attack.

As an initialism CHU is

Chung Hua University, a university in Hsinchu, Republic of China (Taiwan).

As a proper noun Chu is

{{surname|Chinese|from=Chinese}.