One Night Bride (2019)

This is the second season, so it will probably be just as good. Hoping to see how their relationship will further advance

Both have a ML with a hidden identity for the reason of finding their father's killer. Both MLL wear a simple mask and costume to disguise themselves while also making their alternate selves famous.

It's lighthearted, with a strong FL and some great sidekicks. They also both trying to solve cases and both have a happy endings.