If you're looking for manga similar to Boku to Boku, you might like these titles.
Ako Kobayashi is a high school girl eagerly awaiting her prince charming to sweep her off her feet, but she has to overcome one small problem: she is so afraid of guys that she breaks out in hives whenever she comes near one. She even rejects the popular Kei Kitaooji who is the first guy to ever ask her out. However, after Kei learns of Ako's condition, he comes to school the next day dressed as a girl and asks her out again.
Just as he was entering high school, Nanaki Koga experienced a certain accident and fell into a deep coma. After two years, he finally woke up. However, he found that the world had changed. While he was unconscious, a sudden craze hit Japan: crossdressing. Now the newest fad, approximately 90% of Japanese people dress up as the opposite gender. And so Nanaki re-enrolls in his all-boys school, in which every student wears a sailor fuku. And as luck has it, Nanaki has a surprisingly feminine face...
Due to his sister's refusal to come home to work in the family inn, a boy is forced to cross dress by his mother. As time goes by, he comes to rather enjoy it.
Nashi, a high school boy has problems communicating with females. Wanting to change for the better, he reached out to his childhood female friend for help. To his utter surprise and embarrassment, the "method" his friend had came up with is for him to cross dress and work at a female underwear store...?
Hashinomoto Maaya has wanted to marry her little brother Rintarou since she was a little girl. Rintarou seemed to feel the same way, claiming that he wanted to be together with his sister when they were all grown up. Now, after going to separate elementary and middle schools, Rintarou is about to enter Maaya's high school! Maaya is filled with excitement for her school life together with her precious brother. But when she finally sees him, she realizes the true meaning of Rin-chan's words all those years ago. He didn't want to marry his sister, he wanted to be just like her. So now, he is beginning his high school life dressed as a girl...!
Uichiro, a junior high school boy, harbors a secret he cannot share with his childhood friend, Tama-chan. He has been cross-dressing for her because she has a phobia of men.
Amasaki Asuka has finally gotten into the school she wants, a school where Togo Hiroshi, the man who rescued her from a subway groper, works as a teacher. She has a big, intensely sexual crush on him, but he seems to not remember her. When Asuka arrives at the school dorm, the dorm leader, Shiga Kahori, shows her around. Asuka is shocked to realize that she has the same sexual feelings for Kahori! Will Kahori return her feelings?
On his first day of high school, Yuuya Ochi is shocked to discover that the girl sitting in front of him in class is actually a guy named Shigemitsu Izumi. Unable to simply ignore it like the other guys in class, Yuuya can't stop thinking about Izumi and wonders if he's actually a girl, especially after Yuuya sees Izumi waving to a good-looking guy who he suspects is Izumi's boyfriend. Intent to find out more about who Izumi really is, Yuuya follows him after school, only to end up being dropkicked by him over a misunderstanding. Izumi later tells Yuuya that he started cross-dressing to put his twin sister Yurika at ease, who is extremely afraid of guys. However, Izumi confides in Yuuya that he has one other reason why he cross-dresses, something Izumi has never told anyone else.