
She was a tomboy… big emphasis on "WAS".
When he meets his childhood friend again, the one he thought was a boy, he discovers that she was actually a girl, who has grown up to become a beautiful young woman! She takes care of him, they go on a date to the park together, and there are lots of sweet and sour situations!
(Source: Melonbooks)
Bos Geng Cilik yang Kukira Lelaki ternyata Seorang Gadis / Tên nhóc đầu xỏ mà tôi nghĩ là zai hóa ra là con GÁI / The Kid's Leader Who I Thought Was a Boy Is Actually a Girl / ずっと男の子だと思っていたガキ大将が女の子でした / 一直以为是男孩子的孩子王其实是女孩子 / The Gang Leader Who I Thought Was a Boy Is Actually a Girl