Soukou no Strain: At Odds

Sara Werec in her school uniform standing back-to-back with Ralph Werec in his military uniform

What happened to respected ace pilot Ralph Werec? His little sister, Sara, follows in his footsteps and joins the military in order to find out.
From the anime series Soukou no Strain (Strain: Strategic Armored Infantry)

Schwarzesmarken: At Ease

Theodor Eberbach looks on as Lise Hohenstein smiles

Theodor Eberbach and his step-sister, Lise Hohenstein, are pilots in the same East German battle squadron during the brutal war against the BETA alien invasion, so they keep an eye out for one another.
From the anime series Schwarzesmarken

Fullmetal Alchemist: Brotherhood: Bring It On

Alex Armstrong and Olivier Armstrong staring angrily while covered in blood

Don’t mess with Major General Olivier Armstrong or her younger brother Major Alex Armstrong.
From the anime series Fullmetal Alchemist: Brotherhood

Hundred: Small Talk

Hayato Kisaragi bends down to listen to his sister Karen who is seated

Hayato Kisaragi fights dangerous alien life forms known as Savages in order to get the most advanced medical treatment for his wheelchair-bound younger sister, Karen.
From the anime series Hundred