Takumi suffers from a terminal illness, agrees to try an experimental gene therapy and is changed into a girl.

As Takumi Musashino lay in his hospital bed, with his body being consumed by cancer and doctors giving up on him, he knew that his life was coming to an end. At the last minute, a mysterious woman appears with an experimental treatment promising a miracle cure, but warns there might be some side effects. Though the treatment cures him of his cancer, his body continues to change until Takumi has become a full-fledged woman! Takumi hoped the cure would allow them to live a normal life again, but not only has their body changed, their relationship with friends and classmates are now different. With every guy giving them weird looks and wanting to touch their new body, can Takumi navigate their new life as an average woman? 
 
(Source: FAKKU)
 
1, 3-5, 7-8. TSF Monogatari (TSF物語); Comic Mujin 2010-10, 12, kakioroshi, 2011-01, 04, kakioroshi 
2. Ero wa Bungaku! (エロは文学！); Comic Mujin 2010-05 
6. Hitori Nabe x Futari Nabe (一人ナベｘ二人ナベ); Comic Mujin 2008-12

Takumi Musashino was once an ordinary high school boy, but that changed when his body transformed into that of an alluring high school girl thanks to an experimental gene therapy treatment he received after being diagnosed with a terminal illness. She astonishes her classmates with her new body, receiving mixed reactions from them. While girls like Anri Sogahara offer her important adjustment advice, her male peers begin to see her as an object of their desires... 
 
Although Takumi is both confused and nervous about her new being and appearance, she will soon discover the wonderful pleasures of being a young, adolescent woman. 
 
(Source: MAL Rewrite)