Gimai (Imoto) Ga Yusha Ni Narimashita. 4 (Ari an Rozu) [Light Novel]

[Machine Translation] Rio is a high school girl who was summoned by her sister-in-law as a hero and came to another world. Using the power of "Darkness" that she has obtained, she is now working at her own pace to return to her original world. When Rio hears that her sister-in-law, Amane, is heading to the "Sanctuary of the Wind", which has been invaded by many demons, she is worried and decides to go ahead and exterminate the demons. Rio, who had a hard time in the sanctuary where only wind magic could be used, somehow managed to wipe out all the demons. However, the last "wind spirit beast" that appeared in the sanctuary was ineffective with wind magic, and it asked to be "caught without destroying the nucleus and returned to its normal state. Can Rio successfully conquer the wind sanctuary and protect Amane? The fourth installment of this series unravels the mysteries of the world with a sister-in-law whose conscience is a bit of a mess, and the hard-working Rio who supports her from the shadows!

勇者として召喚された義妹に巻き込まれ、異世界へやってきた女子高生、里桜(リオ)。手に入れた「闇」の力を使って、元の世界へもどるためにマイペースに暗躍中。義妹の天音(アマネ)が多数の魔物に侵入された「風の聖域」へ向かうと聞き、心配したリオは先回りして魔物退治をすることに。風の魔法しか使えない聖域に苦戦するもどうにか魔物を一掃したリオ。ところが、最後に出てきた「風の精霊獣」は風の魔法が効かない上に「核を壊さずに捕まえて正常な状態に戻してくれ」って、何その無理ゲー!リオは無事に風の聖域を攻略し、アマネを守ることができるのか!?良心が駄々漏れで危なっかしい義妹と、影から支える苦労性のリオ、世界の謎が解き明かされていく第四弾!