呼ばれるのはHogeのmethod_missingだけ。

parent.rb

module Hoge
  def self.included(klass)
    klass.extend ClassMethods
  end

  module ClassMethods
    def foo
      p 'foo'
    end

    def respond_to_missing?
      true
    end

    def method_missing(method)
      p "#{method} is missing(from module Hoge)"
      super
    end
  end
end

class FugaParent
  def method_missing(method)
    p "#{method} is missing(from class FugaParent)"
    super
  end
end

class Fuga < FugaParent
  include Hoge
  attr_accessor :a, :b, :c
  def initialize(h)
    @a = h[:a]
    @b = h[:b]
    @c = h[:c]
  end
end

p Fuga.new(a: 1, b: 2, c: 3)
p Fuga.ancestors
Fuga.fugaaaaaaaaaa