charbios: Mutsumi Otohime
The young Mutsumi played matchmaker to Naru and Keitaro after it became clear that Naru wanted to go to Tokyo University with Keitaro. She deliberately lost a game of Janken (rock-paper-scissors) which was to decide who out of Naru and Mutsumi would become Keitaro's wife. She then made a promise with Naru that both she and Naru would later go to Tokyo University, so that Naru would remember the promise (she was too young to be able to remember when Keitaro made the promise).
Despite being clumsy in small things and anemic, Mutsumi generally has good luck when it comes to life-changing matters and always seems to come out all right, even if she gets a few bruises along the way. Even more than Keitaro, Mutsumi has the tendency to fall down, run into things, and generally get into injurous situations while recovering quite quickly. She also frequently has near-death experiences. Her outlook on life is somewhat disconnected with reality, a point reinforced by her worldly goods consisting of watermelons, her test study techniques consisting of random chance guessing, and her almost unrealistically optimistic outlook on life. As something of a counterbalance to her inability to do things anyone could do, she has a number of unusual qualities. She can speak "turtlese" (though she claims she can't), and her guessing method for test taking, involving the sides of a pencil, actually got her through the Tokyo U entrance exams.
Her surname, Otohime, comes from the legend of Urashima Taro, where Otohime is the beautiful daughter of the Sea King and the eventual wife of Urashima. Otohime first appears in the legend as a beautiful five colored sea turtle, providing the basis for Mutsumi's association with supernatural turtles. Her character design was supposedly modelled on Aeris of Final Fantasy fame.
The portrayal of the Naru/Keitaro/Mutsumi relationship is somewhat different and more bluntly depicted in the anime.
She gave Narusegawa her Liddo-kun doll when she left Hinata when she was young.
It's a strange way how things turn out. If you were to put Keitaro and Mutsumi face to face, it'd almost be like putting a mirror in their face. As Naru pointed out once, Mutsumi is practically a female version of Keitaro. Like he, she's generally good natured, if clumsy and funny at times, and having a lot of Keitaro's habits.
Also like Keitaro, she seems to have made a childhood promise to someone to get into Tokyo University...and again like Keitaro, she's a two-time Ronin, though not because she has trouble with the test persay. She could easily pass...if she didn't faint the day of the test...or forget to write her name on the thing...you get the problem. Her big failing is her tendency to choke when it really counts. She's anemic and prone to fainting (the first time she and Keitaro met, they literally ran into each other, and she ended up catatonic for several minutes), and she forgets things now and then.