If you're looking for manga similar to Southern Cross, you might like these titles.
Hirasawa Asako really likes advertisement leaflets! Super rich young lady Kazuki Sakura moves to an all-girl high school which just happens to be in the same town in which Asako lives. Two completely incompatible people develop an intense but earnest battle of The Town vs Super Rich Young Lady! Can these two become good friends in the end?!
Deep in the mountains, there is a temple where children with beautiful hair colours have been gathered and have lived together since very young. One day, a newcomer from the outside world joins these children, and he happens to have the rarest colour of them all: jet-black. Unaccustomed to the culture and way of life of the temple-dwellers, how will he fare in this new environment?
Yoshida is taking a college class on Japanese culture, and he's the only student. When he arrives, he finds that the course is taught by an enthusiastic young professor named Manaka. She is fascinated by modern Japanese culture, and the first classes features her lectures about many properties of the otaku and otaku society.