If you're looking for manga similar to Boyish na Kanojo, you might like these titles.
A boyish girl and a gyaru are dating.
The child-like Hatakeyama Tsukushi returns to her hometown to attend high school.
A girl loses a punishment game and must confess to the unpopular girl. Her reaction is surprising.
In kindergarten, Chizuru told her friend Iroha to be her bride when they grew up, and she agreed, promising to get married one day. Now that they are in high school Chizuru still remembers that promise, but she doesn't know if Iroha does.