Death Note: Study Session

Light Yagami helps Sayu Yagami study at a desk while Ryuk the shinigami relaxes on a bed in the background

When Light Yagami isn’t committing mass murder using a supernatural notebook, he’s a hardworking student who often helps his little sister, Saya, with her homework.
From the anime series Death Note

Occultic;Nine: Light the Candles

Aria Kurenaino performs an occultic ritual with candles and incense on a bedroom floor as Takaharu Kurenaino watches while sitting on a bed

Takaharu Kurenaino provides emotional support for his little sister, Aria, even when the circumstances are strange and unsettling to most people.
From the anime series Occultic;Nine

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

Baka to Test to Shoukanjuu: Tea for Two

Yuuko Kinoshita and Hideyoshi Kinoshita seated and drinking from a cup

Yuuko Kinoshita and her younger twin brother, Hideyoshi, might look identical, but they’re quite different. She’s an intelligent, prideful, and irritable member of Fumizuki Academy’s top class, whereas he’s a helpful and kind individual whose true passion is acting.
From the anime series Baka to Test to Shoukanjuu

Masou Gakuen HxH: Tough Decisions

Reiri Hida sits in a chair, while Kizuna Hida angrily glares at her from behind

Reiri Hida is both the principal and commander of the Ataraxia military academy. She gives orders to people like her younger brother, Kizuna, who possess a Heart Hybrid Gear weapon armor that can fight against invaders from another world.
From the anime series Masou Gakuen HxH (Hybrid × Heart Magias Academy Ataraxia)

Himouto! Umaru-chan: Trying Too Hard

Takeshi Motoba happily sits in a room much to the dismay of Kirie Motoba

Even though Takeshi Motoba wants to get along with his little sister, Kirie, his laziness and thoughtless actions usually result in her getting embarrassed and annoyed by him.
From the anime series Himouto! Umaru-chan