Ane Kui Yuusha to Teisou Gyakuten Teikoku no Onee-chan!: Gomi Skill Baka ni Saretsuzuketa Anegui Gift no Shounen, Skill Kakusei Shi Teikoku Saikyou Nanadai Onna Shogun wo wo Otoshima Kuru.

Natsuki is a boy who lived an unfortunate life due to possessing the "Ane-Kui" skill, a power considered completely useless and mocked as a garbage ability. However, when he rises up against an invasion from a neighboring militaristic nation, his skill reveals its true potential. The enemy’s top generals, including the "Flame General" Freia and the "Ice General" Shirayuki, all share a distinctive older-sister archetype. As the conflict unfolds, the world edges closer to peace while the empire’s order is thrown into chaos. Witness Natsuki’s unconventional and over-the-top heroic tale in this fantasy comedy. (Source: ebookjapan)