Shokatsuryou Koumei

Visual novel version
When she was evacuating a village and met Kazuto, she was shocked to see the very "messenger from heaven" helping the people. She begs Kazuto to let her join his army, and he allows her to due to his knowledge that she was a master strategist. The third to join the group. She has a tendency to say "Hawawa" very often to the point of the being called the "Hawawa Strategist" by the soldiers. She also has a hobby of reading perverted books to discover new ways to please Kazuto.

Anime version
A shy, kind, and reserved girl around the same age as Rinrin, but is a smart, good strategist in battle. However, her naive and child-like nature often overshadows these attributes, and has been known to act on the same level of immaturity as Chōhi. She wants to become a great scholar like her master Shibaki. The fourth to join the group. She was also trained in herbal medicine.
In Shin Koihime she is revealed to have taken up her visual novel hobby of reading perverted books.

(Source: Wikipedia)