YOU SAID:

the fly entered through the window and wouldn't leave me alone but when I tried to kill it, it suddenly disappears and gets 10 times faster.

INTO JAPANESE

ハエは窓から入って、私を放っておかなかったが、私がそれを殺そうとしたとき、それは突然消えて、10倍速くなる。

BACK INTO ENGLISH

The fly came in through the window and didn't leave me alone, but when I tried to kill it, it suddenly disappeared and was 10 times faster.

INTO JAPANESE

ハエは窓から入って来て、私を放っておかなかったが、私がそれを殺そうとしたとき、それは突然消えて、10倍速くなった。

BACK INTO ENGLISH

The fly came in through the window and didn't leave me alone, but when I tried to kill it, it suddenly disappeared and was ten times faster.

INTO JAPANESE

ハエは窓から入って来て、私を放っておかなかったが、私がそれを殺そうとしたとき、それは突然消えて、10倍速くなった。

BACK INTO ENGLISH

The fly came in through the window and didn't leave me alone, but when I tried to kill it, it suddenly disappeared and was ten times faster.