Hello! There's a few more cute costumes I want to suggest! This might be a bit of a long list, but hopefully they can be added eventually! Personally, I think these costumes would be great for winter and summer. Thanks in advance!
White Fox Hood Twin (With and Without Hood)

DP Link (With Hood): https://www.divine-pride.net/database/item/400757/costume-white-fox-hood-twin
DP Link (Without Hood): https://www.divine-pride.net/database/item/420426/costume-white-fox-hood-twin-no-decoration
Silver Blinking Eyes

DP Link: https://www.divine-pride.net/database/item/410384/jRO
White Fox Tail

DP Link: https://www.divine-pride.net/database/item/480521/costume-white-fox-tail
Lunatic Igloo

DP Link: https://www.divine-pride.net/database/item/420427/costume-lunatic-igloo
All of these above costumes were found here: https://ragnarokonline.gungho.jp/news/information/costama-frozen8.html
And now for the costumes from: https://ragnarokonline.gungho.jp/news/information/costama-cute4.html
Maid Frill

DP Link: https://www.divine-pride.net/database/item/410387/
Pitaya Garden Glass Parfait

DP Link: https://www.divine-pride.net/database/item/480525/
Big Teddy Bear

DP Link: https://www.divine-pride.net/database/item/480524
Sorry if it's a bit long, but I thought it would be best to put them all together in one post since they were all found. PS Thank you Serene for helping me find some of the links! Thanks for reading