Why can't one marry the duke in the manga?

It might be that the story has a plot twist where their love is forbidden for mysterious reasons. Or perhaps the duke is already committed to someone else or has a hidden agenda that makes marriage impossible.

Maybe because the houseboy has qualities that are more appealing and compatible with the main character. Could be his kindness, loyalty, or a shared vision of life.

Maybe Duke is doing it to achieve a certain goal or to protect someone or something important. There could be multiple reasons behind his actions that are yet to be revealed in the manga.

Maybe Duke has his own motivations or is driven by some internal conflict that we haven't fully understood yet.

Manga has this charm where it can hook you with its creativity and the depth of its plots. Maybe it's the way it presents emotions and adventures that makes it impossible to say no.

I'm reading it because it has an interesting plot and engaging characters.

It could be due to various reasons. Maybe the opponent is too strong or there are unforeseen circumstances.

The main reason could be that Crunchyroll has partnerships and agreements that don't include offering manga. Or perhaps they haven't made the necessary arrangements with manga publishers to make it available on their platform.

Maybe it's because of the lack of proper study materials or guidance. Without clear resources and instructions, it can be tough to make progress.

It could be that doing it would violate the established rules or plotlines of the manga world. Sometimes, certain actions just don't fit the context or the character developments.