mro.rb

class Hello; end

Hello.singleton_class.class #=> Class

# So methods on Hello.singleton_class should be first looked up as instance methods on Class right?

class Class
  def hello
    puts "from Class"
  end
end

class << Class
  def hello
    puts "from (Class)"
    super
  end
end

class << Module
  def hello
    puts "from (Module)"
    super
  end
end

class << Object
  def hello
    puts "from (Object)"
    super
  end
end

Hello.singleton_class.hello

#=>
from (Class)
from (Module)
from (Object)
from Class