Fragrance of an Adult: "I'm not jealous"

It's a new day and Miki's looking at the pictures that she went to hokkaido. She keeps thinking of weather she's jealous or not. She wants to stay in bed and avoid seeing Yuu, Though he won't stop knocking on the door till she gets up. She comes down and there's a BBQ going on in the backyard. It's a family welcome back party for Yuu and, Miki. Miki has realized that she's getting caught up in the atmospere; though she's still doing her best to fight it. Her father suggests they all go out to have some fun together, everyone says yes except one person, Miki. She runs off and goes to a shop where she runs into, Arimi. When she gets home a vase breaks and it looks like they had a fight. What happens to the 6 of them?