As the Older Brother, I Somehow Have to Play the Younger Sister

Foreword to the Conquest Guide:

Dear Brother, as you can see,

I decided to run away one month before I was due to return home.

If you don't want your beloved little sister to be disowned by the family, put on women's clothes and go back in my place.

One more thing: your little sister is watching you at all times~

P.S. Cross-dressing boy, pure romance