Before, she was just an ordinary girl with a penchant for cooking. Now, she has been reborn into another world as Aria, a princess of the Kingdom of Estrella. Remembering her love for the kitchen from her past life, she spends her days peacefully, cooking to her heart's content. Then one day, she is sent off to Jhero Empire as a candidate to be the cruel and merciless emperor's bride. However, due to unexpected circumstances, she ends up staying in the capital and working as the chef at "Cafe Happiness," all while concealing her identity. As her Japanese cooking fills the customers'hearts... and stomachs with joy, the diner becomes the talk of the town, with lines pouring out of the shop each day. Then one day, a mysterious and attractive young man named Lindt decides to pay the restaurant a visit...

料理が得意な平凡女子が、一国の王女に転生!?
生まれながらにして前世の記憶を持つエストレーラ王国の王女・アリア。大好きな料理をしながら平和な日々を送っていたのに、冷酷無比な皇帝の妃候補としてジェーロ帝国に行くことになってしまった…！ 素性を隠しながらしばらく街で暮らすことにしたアリアは、ひょんなことから『しあわせ食堂』でシェフとして働くことに。アリアが作る日本食は人々の胃袋をがっしり掴み、食堂は瞬く間に行列のできる人気店へ。すると、評判を聞きつけた謎の美青年・リントがお店を訪ねてきて…？