If you're looking for anime similar to Splatter Sister, you might like these titles.
Akito Himenokouji and his twin sister Akiko are close - in fact, maybe a little too close for Akito’s comfort, as his sister has an unrestrained brother complex! Though her brother doesn’t take her lustful feelings seriously, Akiko is determined to set the record straight with the other ladies around him, including the three other beauties that live in his dorm and want the boy for themselves. Every morning, noon and night, the girl continues her mission to cross the line with Akito, and she won’t let any girl or sense or morality get in her way - for as long as there’s love, it doesn’t matter if he’s her brother!
Yuu Nagami, a high school student aiming to become a light novel author has a little sister named Suzuka. Suzuka is an excellent student with good grades and great looks, but she's very cold toward her older brother. Every year Yuu keeps failing at the preliminary rounds of the light novel contest, but one day Suzuka reveals a shocking truth. The flirty sibling romantic comedy that Suzuka wrote has won the light novel contest! To make matters worse, Suzuka doesn't understand anything about light novels or moe so she begs Yuu to stand in for her under her pen-name, Towano Chikai!
What do you do when you live together with gorgeous twin sisters who are intent on seducing you? This is the daily dilemma that faces Keita Suminoe, and politely declining their offers doesn’t seem to be helping him! Despite his school friends' jealous quips, and parents who think everything is fine as the siblings are not blood-related, this makes no difference to the brow-beaten boy. Unfortunately for Keita, school entrance exams are just around the corner, and scantily-clad girls sneaking into his bedroom at night is starting to affect his chances of graduation. Can he focus his mind in time, or will breasts, panties and milky-white thighs prove to be too much of a distraction?