What costume should I wear for Halloween?

There will be prizes for the best costume at work. There will be a lot of candy at work, is too much candy a bad thing?

Character: Umi Sonoda
Japanese Name: 園田海未

Game / Anime: Love Live!
Translated: ラブライブ! 
Continuation : Love Live! School Idol Festival
Translated: ラブライブ！スクールアイドルフェスティバル
Continuation: Love Live! Sunshine!!
Translated: ラブライブ！サンシャイン！！
Japanese Name: ラブライブ!

Artist: hitsu