Your & My Secret Series by Ai Morinaga

Two teens see how the other half lives! She: cute but obnoxious, pretty but violent, petite but rude. He: shy and slender and secretly in love with her. When her mad scientist grandfather accidentally switches their bodies - it's freaky Friday, Saturday, Sunday, and every day! Akira Uehara is mortified when his best buddy starts hitting on him, and is embarrassed to look at himself in the mirror in her underwear! He can't wait to get back to being a boy... moreTwo teens see how the other half lives! She: cute but obnoxious, pretty but violent, petite but rude. He: shy and slender and secretly in love with her. When her mad scientist grandfather accidentally switches their bodies - it's freaky Friday, Saturday, Sunday, and every day! Akira Uehara is mortified when his best buddy starts hitting on him, and is embarrassed to look at himself in the mirror in her underwear! He can't wait to get back to being a boy. But Nanako Momoi has other ideas - she is starting to enjoy life in Akira's body! less

In Volume 2, the story becomes more complex when Akira's best friend becomes interested in Nanako Momoi (but the inside is Akira!) Also, Akira starts to go out with Nanako's best friend Shiina and is losing interest in going back into her real body. What

Akira and Momoi have been living switched lives without anyone finding out. But will this last for long? Momoi just started dating Shiina and has no intention of switching back. Shiina, who believes she's dating Akira does not suspect in the least that th

Nanako can't stop thinking about Senbongi, but he's giving Nanako the cold shoulder, making Nanako feel lonely and jealous. Meanwhile, Akira seems to be getting along with Shiina with no intentions of switching back. Akira gives Nanako the OK to go out wi

High schooler Nanako Momoi may be petite and adorable, but she is far from sweet she is obnoxious, violent and has the table manners of a wild boar. Akira Uehara, a dainty, feminine boy has, for some mysterious reason, developed quite a crush on her. One day, Akira stumbles upon Nanako s grandfather, a man best described as a mad scientist... moreHigh schooler Nanako Momoi may be petite and adorable, but she is far from sweet she is obnoxious, violent and has the table manners of a wild boar. Akira Uehara, a dainty, feminine boy has, for some mysterious reason, developed quite a crush on her. One day, Akira stumbles upon Nanako s grandfather, a man best described as a mad scientist. He is performing an experiment on Nanako, but Akira manages to get in the way and suddenly finds that he and Nanako have switched bodies! Akira, the now dainty and feminine female, is desperate to get back into his old body, especially after one of his long-time friends starts flirting with him. Switching back may prove difficult, though. It looks like Nanako is starting to enjoy life as a guy! less