Lol, I so wanna punch Ikki. Reminds me too much of NTR 'antagonists' for some reason (maybe because of his weird looks? I dunno). Doesn't help that Shin/Toma are basically tagged as osananajimi from the get go.
But holy crap, the main heroine is so moe... unusual for otome game based anime. The combination of her situation, her attitude, her voice, and her facial expressions really gives rise to the "I wanna protect her" feeling even without the osananajimi tag. Plus, she really sells the kimono maid uniform, which looks great on her.