Love Is Drop by Drop (2016)

In both the main lead is a single mother whose husband died. There are two men in love with her, one is very rich and rather childish.

Similar concept of the main female lead's first/current love dying and the main lead getting his heart. Transplant and cellular memory plot lines.

Both drama focus on female lead fall in love with the man who has her ex-husband heart.

Both are long dramas with family involved.