There are some similar things between these two dramas. They are thai bl series with secret crush theme. The main characters in both are not confident about themselves.

These are both fantasy korean dramas which are set in fictional historical time and country. Both dramas have magic, spells and prophecies, with royal politics involved.

These two are both fantasy historical korean dramas. Both have sweet love story between leads. Lead actors are very talented and have amazing chemistry. 

These two are both fantasy historical korean dramas. Both have sweet love story between leads. Lead actors are very talented and have amazing chemistry.

These are both fantasy korean dramas which are set in fictional historical time and country. Both dramas have magic, spells and prophecies, with royal politics involved.

MLs - handsome, rich, arrogant CEOs
FLs - kind & cheerful girls from a poor family who is an employee of MLs.
Later they signed a contract to helping each other in different matters. Business Proposal is pure classic romcom. Master's Sun is also a romcom with horror elements. Both couples have very good chemistry.

Both are South Korean dramas.
- Smart and Rich CEOs as MLs. Introverted Boss's ML has some problems about his social life.
- Poor FLs work for him
- Boss-Employee Relationship
- Office Romance

Both are South Korean dramas.
- Smart and Rich CEOs as MLs
- Poor FLs work for him
- Boss-Employee Relationship
- Office Romance

Both Rich and Poor involved.
- Rich Man, Poor Woman is Japanese drama. A Business Proposal is South Korean drama.
- Smart CEOs as MLs
- Poor but hardworking FLs

- Both MLs are CEO 
- Boss-Employee Relationship, Office Romance
- Boss & Me was my first Chinese drama.
- Sweet love stories

These dramas have the main characters being reincarnated from the past, meet in the next life. Their undying love and morale is beautifully written and directed. Finally, they'll probably remember their past lives.

One and Only is the historical part, Forever and Ever is the modern part of this story. Both adapted from Beautiful Bones novel. Both stars Bai Lu and Allen Ren as the main leads.