The story focuses on the relationships of Kasumi Kishimoto, a high school student. When she enters Myōjō High School, she moves into her aunt's boarding house, where four boys attending the high school are tenants. Despite her steadfast determination to stay loyal to her boyfriend, who is studying abroad, Kasumi finds herself slowly falling in love with one of the boarders, Yūsaku.
The story focuses on the relationships of Kasumi Kishimoto, a high school student. When she enters Myōjō High School, she moves into her aunt's boarding house, where four boys attending the high school are tenants. Despite her steadfast determination to stay loyal to her boyfriend, who is studying abroad, Kasumi finds herself slowly falling in love with one of the boarders, Yūsaku.
At a high school entrance ceremony, high school student Kotoko Aihara, who isn't that smart, notices pretty boy Naoki Irie. She falls in love with him immediately. Kotoko initially doesn't express her feelings to him, but finally has a chance to tell him how she feels. Unfortunately, Naoki turns Kotoko down, saying "I don't like dumb women." One day, Kotoko Aihara's house is severely damaged by an earthquake. Until the house is rebuilt, Kotoko Aihara and her father decide to live with her father's friend. When Kotoko Aihara moves to her new temporary house, she is surprised to learn that Naoki Irie lives there as well.
Rentaro Aijo was rejected 100 times in middle school. He visits a shrine and prays for better luck in high school. The God of Love appears and promises that he'll soon meet 100 people he's destined to date. But there's a catch—once destiny introduces someone to him, the two must happily love each other. If they don't, they'll die. What will befall Rentaro and his 100 girlfriends in high school?
Sousuke Aikawa is a part-time worker who lives in a rundown apartment building where his only consolation is that the landlord is a beautiful woman and the girl who lives above him is cute. One day though, the ceiling above him creaks and... Bang! In from the second floor, directly above him, the cute girl comes crashing down on him…!? In an erotic encounter that can only be classified as a miracle, hearts and bodies are connected by chance. Then for some reason, he starts to live with both of these beautiful women!? Under this one roof, just what exactly will become of this crowded love triangle...!?
Misaki Ayuzawa is the first female student council president at a once all-boys school turned co-ed. She rules the school with strict discipline demeanor. But she has a secret, she works at a maid cafe due to her families circumstances. One day the popular A-student and notorious heart breaker Takumi Usui finds out her secret and makes a deal with her to keep it hush from the school in exchange for spending some time with him.
Nanami Takahashi is a high school student entering her first year. Immediately on her first day however, she becomes the victim of a practical joke by the school's most popular guy, Motoharu Yano, who coincidentally also ends up in her class.
For high school students like Shouichi Kamita, university entrance exams and the future are common concerns. It is also during this time in life that a mysterious emotion that vexes people of all ages may begin to weigh upon one's mind—love. At this point in his teenage years, Shouichi finds three girls he could see himself having a future with: the ever-cheerful Hikari Tsuneki, who teases Shouichi without mercy, but actually has a softer side; the competitive gamer, Tooru Miyamae, who has difficulty communicating with others; and Shouichi's childhood friend, Kyouko Touno, the sometimes immature shoujo manga enthusiast. Seiren follows Shouichi's relationships with these three girls across three separate arcs, as their feelings grow from mutual interest and blossom into something more beautiful.
Fuutarou Uesugi is a poor, antisocial ace student who one day meets the rich transfer student Itsuki Nakano. They argue but when Uesugi realizes he is to be her tutor, he tries to get on better terms. While trying to do so he meets four other girls.
Mizuki disguises herself as a boy and transfers to the same all-boys' high school her idol, Izumi Sano, a high-jump athlete who gave up on the sport, attends. In between their classmates' antics she tries to get him to jump again.
In the romantic comedy story, a high school girl named Kotoko finally tells a fellow senior named Naoki that she has loved him from afar since she saw him on their first day of school.
Shiina Aki is constantly being treated like a girl due to his feminine looks so he decides to move to Tokyo to attend middle school in an attempt to change himself. However what awaits him in his new home, Sunohara-sou, is the kind-hearted caretaker, Sunohara Ayaka. Along with the three female members of Aki's new middle school's student council, Yukimoto Yuzu, Yamanashi Sumire & Kazami Yuri. And so begins Aki's new life in Tokyo living with 4 girls.