expression
pay it forward
Wasei-eigo from English 'pay forward'; used for the concept of repaying kindness by helping others rather than the original benefactor. Often used as a noun or in explanatory contexts.
wasei-eigo (Japanese-coined English), from pay forward
See also: 恩送り
ペイフォワードの考え方は、映画で広く知られるようになった。
The idea of paying it forward became widely known through a movie.
彼は受けた親切をペイフォワードで返すことにしている。
He makes a point of repaying kindness by paying it forward.