
If you're looking for manga similar to Negative Twin-Tower!, you might like these titles.
It follows the adventures of a male (who seems to change every few chapters) and a short, humorous, but mostly ecchi encounter with the various females he meets, whether it's in school, in the class room, or in the nurse's office.
Shimei Kanau is a 23-year-old high-school teacher who is really really small. Small enough to be easily mistaken as a grade school kid. One day, when she was cleaning her father's old school office with her perverted class rep, she finds a nude robot. From the robot, she learns that when she was a kid, his father made a wish to an ancient item, "Caramel Dice," to stop her from growing in order prevent Kanau from marrying another guy. Can Kanau collect all the "Caramel Dice" to undo her father's wish and get back her "real" body?
Paradise Gakuen's annual competition Miss Paradise is coming soon! But a major incident occured: one of the girls hoped to be a contestant, Chihiro, had her precious part seen by a boy! Chihiro who holds a principle that she won't let anyone other than her husband to see her naked, wants to become Shiba's wife. Because the latter didn't believe her intention, she decides to prove it, by entering the annual competition!
Wakaba Minazono is a nursing teacher who is looking forward to "blossom of youth." She transferred to Enbutai academy which has an excessively large number of students, over 4000, and is going to be a in charge of "The 13th school infirmary".
Nukumori Amane is a cheerful high school girl who lives her life with innocent enthusiasm. In the process, she often inadvertently changes and enriches the lives of the boys around her. In turning a man away from suicide, showing a student council president he doesn't need to be so strict, and many more situations, Amane's sweet, and bubbly girl power makes a difference.
Kamome is an inventor, and her latest invention is a machine that will restore anyone to perfect health, which she created so her grandfather, Kinkaku, could live a long life. When Kinkaku tries to take a look at the machine, he ends up activating it and losing consiousness. When he comes to and climbs out of the machine, he finds out he's been turned into a child! After a little adventure, Kinkaku decides he must insinuate himself into Kamome's school life in order to protect her. Will Kinkaku ever return to his original body?