With the setting of Edo, we have that the more a wealthy a city grows, the more people will gather, and as a side effect more seeds of discord can easily be found.
In one hand we have Shusuke, a slacker "almost" apprentice of a merchant with a rather large mouth who is pretty skilled in conversational skills and reading into people's intentions. In the other hand we have Rie, and gracious Yamato nadeshiko who is actually an expert swordswoman who has dedicated her life to her skills, who works as a benriya or hired hand / jack of all trades.
What have these two in common? Well, besides their very own interesting backgrounds, we have that the two of them are actually quite indebted towards the same person, which is Shuusuke's merchant "mentor" & Rie's landlord.