The 'King of Kotha' is a story that likely involves a power struggle in the area of Kotha. It might revolve around a character who rises to become the dominant figure, facing challenges and rivalries along the way.
I'm not sure exactly who the main characters are in the 'King of Kotha story' as I don't have detailed knowledge about it. But usually in such stories, there would be a protagonist who aims to be the king, and likely some antagonists who oppose him or her.
Typically, 'bangla premer golpo love story' might feature strong family influence. In Bangladeshi culture, family plays a big role in relationships. So, the story could have elements of family approval or disapproval of the love.
Family values play a significant role as well. In Bengali golpo love stories, family approval or disapproval can be a major factor in the development of the love story. Sometimes, the characters have to fight against their family's wishes to be with the person they love, while in other cases, they abide by their family's decisions which leads to a different kind of love story, often a tragic one.
One possible theme could be the fear of the unknown. Since it's a horror story, the 'bhuter' (if it's a supernatural entity) represents something that people don't fully understand.
Unfortunately, without more context, it's difficult to provide the full story of 'bou kotha kou'. It could be a name of a story within a small community or an emerging piece of literature. If you could give some more details like where you heard it from or what kind of story it is (e.g. a love story, a mystery) it would be easier to answer.
One popular Bengali golpo love story is 'Devdas'. It's a tragic love story where Devdas and Paro are in love but are kept apart by society and family norms. Their unfulfilled love is heart - wrenching.