My wealthy ex-wife

In order to protect the male protagonist's self-esteem, the female protagonist concealed her identity as a president of a wealthy family and got married for five years, but was disliked by the male protagonist as a burden and asked for a divorce. After the divorce, the male protagonist learned of the female protagonist's identity and also learned that the female protagonist died of a serious illness. He began to miss the female protagonist's goodness and regretted it deeply...