Dame-dashi (駄目出し): putting out the no-good. Pointing out faults and weak points. The word comes from the theater, where dame o dasu means giving an actor notes on what is wrong in the performance.
Mada mada da ne (まだまだだね): not there yet. The catchphrase of Echizen Ryōma, the hero of the tennis manga Tennis no Ōjisama (The Prince of Tennis).
Chūgen mimi ni sakarau (忠言耳に逆らう): loyal advice offends the ear. The Daijisen dictionary traces the saying to Chinese sources such as the Records of the Grand Historian and explains that advice tends to hurt the listener’s feelings and is seldom accepted with an open mind.