YOU SAID:

this party is Billie Eilish themed

INTO JAPANESE

このパーティーはBillie Eilishをテーマにしています

BACK INTO ENGLISH

This party has a theme of Billie Eilish

INTO JAPANESE

このパーティーのテーマはBillie Eilishです。

BACK INTO ENGLISH

The theme of this party is Billie Eilish.

INTO JAPANESE

このパーティーのテーマはBillie Eilishです。

BACK INTO ENGLISH

The theme of this party is Billie Eilish.