I'm really impressed by how Mei Kinosaki—a queer, female-presenting man—is treated as one of the main characters of Marriagetoxin. He's portrayed over and over as a paragon of sex appeal, of desire, of feminine charm, of what many shonen viewers expect a female romantic lead to look, act, and sound like. He is shown as irresistible to both sexes, and in the openings and ending sequences, he's sexualized, romanticized, and adored for his personality in equal measure. His cross-dressing isn't used for cheap comic relief jokes (outside of the initial reveal). Instead, our main character doesn't question Kinosaki's choice to present as a woman, and just fucking rolls with it.
And this is a shonen anime. A harem shonen anime. They not only made one of their two main characters unabashedly queer, but the series depicts him as the exact person we're meant to see as Gero's romance interest. We are meant to view him as the ideal partner, the beautiful, alluring, kind, good person who we want our protagonist to end up with in the end.
To put it simply, we, the audience, are meant to love him. And I can't emphasize enough how fucking refreshing that is.