Gongjangnim, Jebal Jom Manghaseyo!

Nellie Pepper, land steward to the paranoid psycho Duke Lionel Alterwood, dies from overwork after three years of torture. As she closes her eyes, her final wish is to get revenge. Miraculously, she soon wakes up on her first day of work again! Ready to sabotage her cruel boss, she embarks on all sorts of wicked plans. However, every attempt hilariously backfires, and she ends up improving the duchy instead! Will Nellie be able to enact her revenge and finally make the duke fail for once?
(Source: Tapas)