At the 00:40 mark of the new preview for My Hero Academia season 2's second cour, you can listen to a snippet of J-rock band amazarashi's new opening theme for the show, which is titled " Sora ni Utaeba" ("If You Would Sing in the Sky").
There won't be a new episode next Saturday, July 01 so the second cour will kick off on July 08. The new arc will focus on Tenya Iida's hunt for the hero-killer Stain, who greviously injured his older-brother- the Pro Hero, Ingenium. The next arc also focuses on Deku's training with All Might's former teacher, Gran Torino.