最近、妹のようすがちょっとおかしいんだが。 1 (ドラゴンコミックスエイジ ま 4-1-1)

[DeepL Translation - needs review] Introduction to Volume 1: Mizuki Kamizaki is confused about her life with her new brother after her mother remarries, when a ghost girl named Hiyori possesses her!　The only condition for Hiyori to become a Buddha is to make love with her adored brother!　In addition, she wears strange underwear... Mizuki, the "younger sister", is in for a world of hardship!

(Translator: DeepL)