Kunoichi Indochuu: Yuzuha Kikyou-hen

Tasuke managed to fulfill his desire for a reunion with his childhood friend Yuzuha (nicknamed Yuzu-nee) after 10 years. Yuzuha, who is now an adult woman, finds herself extending him an invitation to deepen their bonds as man and woman. However, Yuzuha has a secret and a purpose for doing this...?

(Source: Melonbooks, translated)