If You Get Bigger, You Have to Report the Class Rules to the Teacher, Ookiku Shichattara Sensei ni Houkoku Shinakya Ikenai to Iu Gakyuu Rule, The Class Rule Where If You Get Bigger, You Have to Report It to the Teacher, 大きくしちゃったら先生に報告しなきゃいけないという学級ルール