【EBA】The 13th of Koshida Siblings: How to Corrupt the Arrogant Sister

This is the first time I’ve been able to get my hands on one of these.
You can’t escape from this kankei

A young girl with an arrogant personality, Chie, gets lost in the mountains with her sister, Kanna, and her brother, whom she hates.
With no phone service and limited food, Kanna is sexually trained by her brother.
It’s a great way to get to know the people in your life.
In addition to the title series, the book also includes a short story and an extra story that was drawn only for the book [13 days of the Koshida siblings]!