If you're looking for anime similar to The Rules of The Brothers, you might like these titles.
Sayama is a gloomy guy that wears a mask to school every day. What will happen when bad boy Saikawa attempts to rip it off?!
A boy who lives with his father after his parents divorce. He meets a girl named Shiori Satou at his father's research lab, and they begin a relationship that is slowly blossoming into love. But everything changes when their parents decide to marry each other, and they decide to move to a parallel world where they are not stepsiblings.
Mizuto and Yume, a former couple who enjoyed a relationship in junior high school, but became more and more irritated at each other, and used their graduation as an opportunity to break up. But on the day before entering high school, the two reunite in the most unlikely way: with their parents announcing a marriage, with Mizuto and Yume now becoming step-siblings. Wanting to prioritize their parents' relationship, the two promise to not fool around with each other, establishing a rule where "the first one to get aroused" loses.
When Chii’s father remarried, she gained more than just a stepmother - she also became the stepsister to thirteen brothers! And as if her now massively-sized family isn’t enough to handle, the girl also learns that they’ll be moving in together! Chii’s new brothers are eager to help her feel welcome, but with everyone living together without parental supervision, the arrangement might lead to more than just new friendships...
Miki is a normal high school student, living a normal life, but one day she is welcomed home with an announcement: her parents have decided to get divorced and switch partners with close friends of the family. The reason? Love. But to add to Miki's disbelief, she may get a new "brother," and he may just happen to be in love with her...
The story begins with Masaki Michishita, an ordinary prep school student who is rushing to the bathroom in a park one day. Despite his rush, he spots Takakazu Abe, an exceedingly handsome auto mechanic sitting on a bench. The two exchange looks, and after Abe utters "Yaranai ka" (Shall we do it?), the two begin their encounter.
Kunieda Kei is a popular TV announcer known for being a cool and flawless professional. But on the inside, he’s the opposite: brash, hot-tempered, and as prickly as can be. Still, Kei juggles his private and professional personas successfully until one day, the unthinkable happens: stop-motion animator Tsuzuki Ushio from work sees him at the grocery store with his real personality on display! Now Kei has to figure out how to navigate a relationship he didn’t expect. But is that really as scary as the possibility that someone might love both sides of him?
Second-years Mao Tsuchiya and Hisashi Otomo make three promises: 1) That Mao will never tell anyone that Hisashi is gay and has a boyfriend, 2) That Hisashi will never think of Mao “in that way,” and 3) That they’ll always knock before entering, in case someone is having some “private time.” The two’s ground rules should ensure a peaceful life together in their dorm, but life is never as simple as it should be, and some things are not so easily promised…
On the eve of Imperial rule in Japan in the mid-19th century, supporters of the Tokugawa shogunate and supporters of the imperial court clash over the country’s leadership and its place in world affairs. Despite being members of clans with opposing political and social views, Touma Kusaka and Keiichirou Akizuki find that they share an interest in foreign cultures and a vision of a more open and progressive Japan. What starts as a meeting of minds eventually blossoms into a romance, but bound by their clan ties and social positions, Kusaka and Akizuki struggle to find happiness as time, distance, political upheaval and the Boshin war conspire to keep them apart.
Mira Munakata is a typical high school freshman; he goes to school, hangs out with friends, and has sex with his father. Ok, maybe not so typical. With the affections (and advances) of everyone from childhood friends to senior classmates, Mira has a wide selection of prospects to choose from; but the only one he really wants is his loving (literally) father Kousuke. So, when Kousuke stays out late and is rumored to be married to his beautiful co worker, what’s a boy to do but cry?