A Troubled Prince!? is the twentieth chapter of the Oushitsu Kyoushi Heine manga.
Heine is surprised to see Leonhard unusually focused on his writing. He explains that he is writing down all the questions for things he did not understand while studying, and bombards Heine with all sorts of questions. He mentions that it's the first time he ever felt excited about studying. He then asks Heine how babies are made, and Heine refuses to answer the question.