The more a city like Edo grows wealthy 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.
On the other hand we have Rie, a gracious Yamato nadeshiko who is actually an expert swordsman
who has dedicated her life to her skills, and works as a benriya or hired hand / jack of all trades.

What have these two in common? Well, besides their very own interesting backgrounds, the two of them are actually quite indebted towards the same person, which is Shuusuke's merchant "mentor" & Rie's landlord.