Takamizawa is, at first, a sort of an older sister figure to Shotaro, but later on tries to become more of a parental figure to him. At Kenji's suggestion, she stays overnight with Shotaro at Kenji's house to protect the boy. She shortly after turns this around by telling Shotaro that it's the other way around, Shotaro protecting her, in order to avoid damaging his pride. Takamizawa and Otsuka get along more like father and daughter.
Her relationship with Kenji is much rockier, however, as she is first introduced to him when he is still a wanted criminal. After he saves her from drowning in episode 21, giving her mouth-to-mouth CPR, she begins to think he is attractive, but then begins wailing about "ruining" her marital future for indirectly kissing him. In the same episode, when the two are disguising themselves in the skintight PX Syndicate soldier suits, Takamizawa makes a veiled pick-up about her body, which fails, and she ends up slapping Kenji.
Takamizawa appears to hold at least some sort of affection for Murasame, which is never returned, save for him kissing her in exchange for Takamizawa keeping quiet about his faked death. She at first is horrified that he is leaving Japan, but loudly promises to find "a better husband, and we'll have lots and lots of healthy kids!" She appears to target masculine-looking men with "chiselled features", such as Johnson and Kenji.
In the 2007 Movie Edit
Takamizawa (credited this time as Ahiru Takamizawa) is converted into being Kenji and Ryuusaku's criminal lackey, and Kenji's girlfriend. She is a self-proclaimed "shotacon", and upon meeting Shotaro, cuddles him menacingly. (Note: There is a picture of this, seen on a Japanese site in May 2009. If anyone finds it, either put it up here or notify me, because I have a funny caption for it.) Takamizawa's entire outfit changes for this movie, and her personality becomes more extroverted.