The main character Udagawa Gosuke has received his father's dojo, mainly because his father and older brother were made to commit hara-kiri. He wasn't really supposed to get it simply because he's a second son. But due to the way his pops and brother died, he doesn't have a whole lot of self confidence, so he practices fencing day-by-day at a nearby dojo. However, because the people at that dojo are asses, he soon tries to invent a dojo and a style for people who just enjoy it.

However what really sets this aside from most shounen is that the main male and female characters are actually married. (At age 15 no less!)

The girl Utagawa Shino is the younger sister of his senpai, and is a bit...weird, to say the least. She makes rabbit masks to help bring in a bit of money, although to say that she's obsessed with rabbits would be an understatement. She claims it's because "the rabbits will someday reach the moon." When Gosuke invents his new dojo, he decides to make a style of swordsmanship known as "Rabbit Style Fencing."