Futari no imôto: Mushaburi hatsujô hakusho(2008)

Junichi begins living with his girlfriend, Makoto, an insurance salesperson, at her house. Makoto's house is also home to two sisters: Rin, a NEET and cosplay enthusiast, and Kaoru, an aspiring actress who keeps failing auditions. With Junichi in a harem situation, the frustrated Rin and Kaoru begin aggressively pursuing him. Although Junichi fears the jealous Makoto, his lower body reacts anyway…