This is the fight beyond death.
Every shinigami has to go through it. Whether they're in 3rd, 6th, 11th, or even 1st Division in the Gotei 13, every shinigami passed through these halls. Learning and specializing in Hand-to-Hand combat, Demon Arts, Technological Sciences, or even Investigations, the shinigami who leave the Academy are Gotei 13's finest.
There's only one problem. You have to survive Shinigami College Life before you can get there.
In a Soul Society different from the one Kubo paints for us, the prospective Gotei 13 members have to hold their own ground amid Arrancargami, Quincygami, and Vaizardgami, failing grades from Professor Kuchiki Byakuya, bonding experiences with Professor Kurotsuchi Mayuri, kidou training with Professor Aizen Sousuke, and dorm life with Professor Shihouin Yoruichi as Resident Director.
This is The Shinigami Academy.