お花見しようよ！ — Let's go cherry blossom viewing! (Cultural · Seasonal, Casual — to friend, JLPT N4)

Gesture & etiquette

An excited, slightly raised voice and bright expression suits this casual invitation; a pointing gesture toward the outdoors or a map can add visual clarity; enthusiastic agreement ('乗った！' notta = I'm in!) is warmly received.

Hanami (花見) is a cherished spring tradition of gathering under blooming sakura to eat and drink together. Reserving a spot with a picnic sheet early in the morning is standard practice (called '場所取り', basho-tori). It's perfectly acceptable to bring store-bought food — the key is the togetherness, not elaborate cooking.