Critics have commended the anime series for its portrayal of strong friendships as well as for its large cast of "strikingly different" characters who have different dimensions and aspects to them as the story continues and for an ability to appeal to a wide audience. Writer Nicolas Penedo attributes the success of "Sailor Moon" to its fusion of the shōjo manga genre of magical girls with the "Saint Seiya" fighting teams. According to Martha Cornog and Timothy Perper, "Sailor Moon" became popular because of its "strongly-plotted action with fight scenes, rescues" and its "emphasis on feelings and relationships", including some "sexy romance" between Usagi and Mamoru. Usagi and Mamoru's romance has been seen as an archetype where the lovers "become more than the sum of their parts", promising to be together forever. In contrast, others see "Sailor Moon" as campy and melodramatic. Criticism has singled out its use of formulaic plots, monsters of the day and stock footage.