เมื่อวันหนึ่งมีเด็กสาวที่ไม่ทราบจะมาก่อนมาเป็นน้องสาวของพวกเรา แล้วพาเรื่องยุ่งๆของหัวใจมาปั่นป่วนให้จะต้องเชิญชวนคิด ในฐานะพี่ชายมือใหม่จะต้องมานะอย่างไรดีนะ?
Saikin, Imouto no Yousu ga Chotto Okashiinda ga. follows a family simply getting down to construct. once they marry, Mr. and Mrs. Kanzaki bring a young son and girl on for the ride. however highschool freshman Mitsuki Kanzaki is a smaller amount than excited. Stinging from a history of absent and abusive father figures, she is slow to simply accept her stepparent and half-brother. But once Associate in Nursing accident lands Mitsuki within the hospital, she finds herself possessed by the ghost of Hiyori Kotobuki, a lady her age UN agency was deeply smitten with Mitsukis half-brother Yuuya. Hiyori cannot expire to her final reward as a result of her nonreciprocal love for Yuuya, which means she has got to consummate it... in Mitsukis body?! Now, Mitsukis life depends on obtaining Hiyori to Heaven. however can she get wont to sharing herself with a aggressive, amorous ghost? will she overcome her distrust of her new family? will she bring herself to satisfy Hiyoris feelings for Yuuya? And would possibly she be activity some feelings of her own?