YOU SAID:

Summer after high school when we first met.

INTO JAPANESE

初めて会った高校卒業後の夏。

BACK INTO ENGLISH

We first met in the summer after graduating from high school.

INTO JAPANESE

初めて会ったのは高校卒業後の夏でした。

BACK INTO ENGLISH

The first time we met was the summer after we graduated from high school.

INTO JAPANESE

初めて会ったのは高校卒業後の夏でした。

BACK INTO ENGLISH

The first time we met was the summer after we graduated from high school.