Megumi is Keiichi's little sister in age, but bigger sister in height. Whether she can be considered a major character is debatable, but she's around a lot and is featured in a few issues of the manga. Keiichi and Megumi are close siblings, and she visits his house often. Ever since they were kids, Keiichi has looked out for her. In the present he often acts annoyed when she's around, but is still the supportive brother he's always been.
Megumi is the most normal character in the entire series. Despite the never ending super natural phenomena happening all the time, Keiichi somehow manages to keep the fact that he's living with goddesses a secret. Like nearly everyone, Megumi quickly takes a liking to Belldandy, and seems to be comfortable with Urd and Skuld as well. About the only thing that Megumi finds really strange about her brother is that he's been living with his girlfriend for so long and that they haven't gone "all the way".
The Morisato family has a long heritage of loving motorcycles, and Megumi seems to have picked this up from her brother. She rides a 80cc KSR that she takes very good care of. She's very knowledgeable about motorcycles, but her own ride is completely stock. Megumi is around the NIT motor club a lot, but isn't an actual member. Keiichi remarks that if the softball team folds, Megumi could join the motor club, so likely she's not interested in it.
In her own words...
- of course it's no fun losing, but it's still lots of fun to play isn't it?
- Keiichi, are you really... a man?
- Wha-? How did I get here?! Ohmigod! Maybe... I'm a SLEEPWALKER?!
They make such a cute couple don't they?