Chapter 9: Brotherhood/Companionship
My favorite: Undecided. Winners so far are: The Card Apprentice & Martial Arts Master
Slight spoilers:
In Card Apprentice, their first time making card plays and how they watch each others back was true brotherhood. In MAM, his friend Casanova helping him with his budding relationship and supporting him as a bro. These bros can shine outside of knowing the MC. While I wish they stuck around more throughout later chapters, the earlier chapters are great examples of how you should write a good bro.
I leave this category as to be determined because I'm lacking in examples, or I'm forgetting to remember cases where bros are still around near the end of novels and serve a purpose other than being a fancy male flower to make the MC glow shinier.
CREATORS' THOUGHTS 
Tim_
Tim_ I'm dying to read about an MC who doesn't go it alone. Secondary characters who impact the world. Give shout-outs to your favorite novels that have great companionship in the comments.