回李

Etymology
From. The figurative use of is from the following line in the :
 * Original Chinese: 投我以桃、報之以李
 * Japanese reading:

Noun

 * 1)  return; repayment
 * 2)  reply letter
 * 3)  messenger sending such a letter

Verb

 * 1)  to send a return letter, to reply in writing