Shizuma is a trainer of the Varied Tit.   (Source: Wikipedia) 

In a school where after school activities are mandatory among all students, Hajime and her friend Sayo come across a new club that they have never seen before. The club is called "The Cultural Activity Preservation Club." The two enter the room to find all kinds of analog jobs and activities, such as handcrafting mats and toothpicks. This is a unique cultural manga mixed with comedy so as not to bore you, this is Double J!<br><br>
(Source: Mangahelpers)

A Japanese voice actor. She's also a certified junior and senior high school teacher.

Hirohashi was born in Niigata Prefecture, and her family's home was a Buddhist temple. Because of this, she attended Ryukoku University in Kyoto, a Buddhist university. In the middle of her first year, however, her parents told her that she could do what she liked, even if it wasn't related to Buddhism, so she sought out what she wanted to do. During her second year, she remembered a radio show she used to listen to in middle school and became interested in voice acting, so she started going to the Aoni Coaching School Osaka while attending university at the same time. The radio personality she had listened to in junior high school was a voice actor, which inspired her to become a voice actor herself.

Non-anime roles:
• Mast - Goddess of Victory: Nikke

Shizuma Sanada