Let's Do It Already! manga volume 6 features story and art by Aki Kusaka.

The couple has finally headed off on their romantic school trip. But Yuri gets ahead of herself and gives Keiichiro a kiss on the forehead, which suddenly triggers the Katsuragis into high-alert mode! Keiichiro's older brother, Shotaro, arrives on the scene. At first the two think he's come to give them a scolding, but something is off about the way he's acting!