The bride is seventeen

Hanayome wa Juunanasai
花嫁は十七歳

Source

Hanayome wa Juunanasai
花嫁は十七歳
novel

Born as the youngest of five siblings, Sakurako is 17 years old and attends an all-girls school. However, her true identity is actually… a man! Sakurako was raised as a girl by her mother who wanted a daughter, but her mother's outrageous behavior didn't stop there. Because she wanted to see Sakurako in a wedding dress, she decides to arrange for Sakurako to marry her best friend's son! Femboy high-schooler Sakurako's newlywed life?! (Source: Prism Bunko, translated)

Sequel

Shin Hanayome wa Juunanasai
新・花嫁は十七歳
manga

Due to her mother's outrageous desire for a daughter, Sakurako lives as a woman even though she is a man. On top of that, Sakurako is married to Kazuhiko, a popular mystery writer, so the high school boy is also a married woman. The two of them have been living a sweet married life, overcoming various obstacles, but when Kazuhiko comes to Sakurako's all-girls school as a new teacher, Sakurako's life becomes even more complicated! A rival classmate tries to seduce Kazuhiko, and Kazuhiko wants to have sex with Sakurako on campus. How will she get out of this mess? (Source: Aqua, translated)