Hello! So I'm recommending 2 costumes in one suggestion, but the only difference is one has decorations and the other doesn't. They're simply ADORABLE!

Link to the page: https://ragnarokonline.gungho.jp/news/information/costama-cute4.html
DP Link (with decorations): https://www.divine-pride.net/database/item/420433/
DP Link (without decorations): https://www.divine-pride.net/database/item/420434/
(PS: Thank you Serene for finding the links!)