日本の夏といえば祭りだ (Nihon no natsu to ieba matsuri da, When you speak of a Japanese summer, [you think] festivals).
You’ve likely already been to a 伝統的な祭り (dentō-tekina matsuri, traditional festival) in Japan. もし行ったことがなくても心配しないでください。今からでも遅くない祭りを紹介します (Moshi itta koto ga nakute mo shinpai shinaide kudasai. Ima kara demo osokunai matsuri o shōkai shimasu, If you’ve never been to one, don’t worry. [Here, we] will introduce some that are not too late to join even now).
If you’re new to 祭り (matsuri, festivals), then it’s worth starting your education with the 日本三大祭り (Nihon San-dai Matsuri, “Big Three” Japan festivals). The 神田祭 (Kanda Matsuri, Kanda Festival) in Tokyo has come and gone but you still have a chance to see the two others.