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performing a part in one's own play; playing a musical piece that one has written
doing everything by oneself (from preparation to execution)
put-up job; charade
sock-puppeting (i.e. pretending to be more than one person on the Internet)
自作自演で劇を作った。
I created a play doing everything myself.
自作自演の疑いがある。
There's suspicion of a put-up job.
自作自演で問題を解決した。
I solved the problem by doing everything myself.