Brothers is the twelfth chapter of the Oushitsu Kyoushi Heine manga.
Heine bumps into Bruno and Licht having another fight. However, this fight seems to be more heated than usual, culminating with Licht saying he wishes Bruno wasn't his brother. Licht then rushes off to town, even though lessons are about to start. Bruno tries to play it off as nothing, but is clearly remorseful, because he lost his temper before and snapped at him instead of being patient with him. At dinnertime, Licht still hasn't come back yet, since he's not sure what to say to Bruno. Just as he plans to stay somewhere else for the night, Heine shows up and tells him to apologize to Bruno, saying that he's sure Bruno would understand. But Licht says it isn't that simple and that no one could understand another's feelings so easily. However, Heine tells him to apologize anyways since he knows in his heart that he wronged Bruno. Meanwhile, despite protests from the guards, Bruno decides to head out to search for Licht. Heine waves Bruno over, and Licht apologizes to Bruno in tears and gives him apple pie. Bruno apologizes as well and pats him on the head, prompting Leonhard and Kai to want pats on their head as well. Bruno reveals to Heine the reason for their quarrel was because Licht stole his piece of apple pie at breakfast. Heine is perplexed over the fight over something so trivial, and thinks that the bond between brothers is most curious.