Ya¹sui⁴-ch'ien² Literally "age-warding money". Pinyin romanization would be Yāsuìqián (压岁钱)

Like otoshidama, yasui-ch'ien is given by elders to the younger generation. As the envelopes are usually red (symbolizing good fortune), they're also called hung-pao, 'red envelopes'. The amounts of money found within are often in even numbers, which are seen as lucky.

Such a joyous piece of red paper! Contrast this with "red papers" in WWII Japan, which were draft notices, not money envelopes. Japanese otoshidama are in white, not red.

Yaaaay!