Mori Satoru (毛利学?) was the principal of Majisuka Jyogakuen in Majisuka Gakuen 5 and Cabasuka Gakuen. In both timelines, he was loved by the Majijo Yankees after showing that he cared for the their well-being.
Majisuka Gakuen 5
In Majisuka Gakuen 5, he resigned after a series of incidents that led to deaths of Majijo students and former students. However, he was revealed to be the culprit behind Salt's death, which lead to the Yankee-Yakuza War. Mori was killed by Center using the same gun he used to murder Salt.
In Cabasuka Gakuen, he informed Rappapa of the school's financial crisis, which could lead to the school being closed down. This lead to that timeline's president, Sakura, to leave school for a while and open a Cabaret Club Business to help the school. This shocked Mori and expressed his concern, in which the Rappapa members assured him that they will be okay. Mori was later seen at the school grounds in deep thought.