Granzreich Family Edit
Bruno cares for Leonhard and Leonhard cares for him too. Leonhard calls him dearest brother, and he also respects him due to his intellegence. Bruno is somewhat jealous of Leonhard because Leonhard's naivety allows him to come up with solutions that Bruno never thought of.
Bruno argues a lot with Licht and this maybe caused by the differences in their personalities and their ways of doing things. Despite their differences, he cares a lot for Licht and Licht cares from him too. For example, when Licht told Bruno that he hated him, he felt that he did something wrong and wanted to apologize when he came back. When Licht was staying out too long, Bruno wanted to search for him because he's cares for him, even if Licht doesn't feel the same (that's what Bruno thought).
Leonhard is protective of his sister. When Heine pretended to be engaged or married to Adele, Leonhard was going to stop that from happening, and he wants her to marry someone worthy.
When Bruno was younger, he felt that he was inferior to Eins and never thought that he could catch up to him. This caused him to study and work hard to because great. He respects his brother but finds him scary in a way.
At the beginning, Bruno did not believe that Heine would be a good tutor for him because he didn't go to college, and there was nothing else that Heine could teach him. After testing Heine in various fields of skills, he saw the brilliance of Heine and calls him master. He believes of himself as Heine's apprentice.