For example, the shi title is common in the speech of newsreaders.
Touma's younger sister, Relena, calls him oniisama.
But what we also see with this particular section is that the phonetics of grandfather and uncle are nearly identical! For example, a character may call their mother okaa-san but then talk about her to their friends using haha no, not the laughing sound! First of all, the kanji is the same when you are using both respectful and humble language, but the readings pronunciations change.
Again, this is the version of the word that is specific to your own older brother.
In English, we have a singular phrase that allows us to express those very words to someone.