Concubinage Record (2015)

Both have a male lead who time travels to the past into a Harem. Similar comedies in both but Man Comes to Tang Dynasty focuses more on the comedy aspect while Concubinage Record focuses more on case solving.

Also, the time travel is completely logic-less in Concubinage Record. ML possesses a body to time travel yet modern equipment also time traveled with him somehow.

It has Main Character from 20th Century going in the Past. Using his Knowledge of Future to Earn Reputation and Money in Past