Mechamaru’s contingency plan was really perfect
Kyoto jujutsu students have no survival rate.
In the Shibuya arc Mechamaru guides Sukuna’s vessel Itadori yuji in the shibuya arc. This contingency plan was activated when the strongest jujutsu sorcerer in the world Gojo Satoru gets sealed in the prison realm by Suguru Geto and his mates.
Mechamaru clearly says apart from todo, Megumi Fushiguro and Itadori Yuji other jujutsu high has very low survival rate this made the kyoto jujutsu high students angry but in the recent episode of jujutsu kaisen season 2 nishimiya, miwa and kamo everyone collectively attacked Suguru Geto with their ultimate attacks but in reality nothing happened to Geto and he easily crushed the sword of Miwa easily.
Mechamaru clearly prescribed in his plan that among his colleagues only Todo has a 100% survival rate. Now this only proves how perfect Mechamaru’s contingency plan is.