Infinite Stratos - Season 1 Episode 10 Thin Red Line
Overview: After catching the girls listening at their room while Ichika is massaging her, Chifuyu has a talk with the girls about their feelings for her brother and gives them some advice. The next day, Tabane arrives to personally deliver to Houki the Akatsubaki, a fourth generation model with abilities far more advanced than the others. However, Chifuyu soon receives news that an an unmanned IS called the Silver Gospel has gone out of control. After assessing the situation, Chifuyu orders the group to stop it, while Ichika and Houki will pursue it, as only they would be fast enough to catch up with the Silver Gospel.