This Small Incident Occured Ten Years Ago - S1.E55

Shoheiko, the official Shogunate college, has an admissions scandal where the bureaucrats turn out to have been accepting bribes for admissions. Yoshimune suggests opening it to commoners and calls up some obscure scholars; the vicious bureaucrats attack and kill one. Shin-san absolutely loses his mind, but Tatsugoro is there to give him a helping hand.