This app was mentioned in 2 comments, with an average of 1.50 upvotes
バトルガール "Battle Girl" https://play.google.com/store/apps/details?id=jp.colopl.bgirl&hl=ja
http://wiki.dengekionline.com/battlegirl/
Made by, COLOPL, Inc.
The source is the Battle Girl High School loading screen