In the original four panel comic, the main character Cocoa arrives at the cafe Rabbit House one day, excited for rabbits. She actually all but lives in that café. She meets lots of different girls there, including a tiny and cool girl named Chino, a tough and soldier-esque girl named Rize, a spacey and quintessentially Japanese girl named Chiya, and the ordinary but dignified Sharo.

[From Anime News Network]

Gameplay of Wonderful Party is divided into 2 parts that illustrating the daily life of Rabbit House Cafe. In the first one, player need to enliven the shop in order to prepare Chino's birthday party. The main focus in this part is to set up the shop and dialogue between characters. While the second part, player must set up the shop for a Christmas party. In this part, player will play as Cocoa and story will focuses on which character Cocoa developing a relationship the highest with.