Because I Don't Like My Big Brother At-All--!!

Nao Takanashi has long been trying to tempt her brother, Shūsuke, into entering an immoral (i.e. incest) relationship with her, with Shūsuke barely being able to resist. Nao goes to great lengths for Shūsuke to think of her perversely by d…

It turns out that Nao and Shuusuke are not related by blood. While most people would be upset after finding out something like that, Nao took it in the most positive way possible - it meant that there was nothing to get in the way between …

Iroha coerces Shūsuke into going on a date with her, and Nao decides to follow them, while her friends, Haruka and Hirono, decide to tail her as well. Iroha takes Shūsuke various places including a movie theater, an arcade and a swimsuit s…

Nao coerces Shūsuke into going to the beach with her, though coincidentally they end up running into Haruka, Hirono and Iroha, who Nao recognizes as the pigtailed girl from Shūsuke's childhood photos. Nao and Iroha end up competing with ea…

While running back from buying a new porno magazine, Shūsuke bumps into another person. They get their packages mixed up and Shūsuke ends up with a Boy's Love magazine that he immediately rips to shreds. When the other party, known as Mist…

After having Iroha spy on Shūsuke and Mayuka the previous night, Nao tries putting on black pantyhose and clinging onto Shūsuke as he sleeps. Iroha and Mayuka later arrive, leading to an awkward confrontation. Mayuka ends up questioning wh…

Shūsuke and his friends go on a trip to Akihabara in search of adult goods while Nao and Iroha decide to follow them. After visiting an adult DVD store, the group gets into an argument about their desired fetishes and break off in search o…

When Shūsuke gets a report about him failing in all of his subjects, he then realizes that he has to take a follow-up exam or risk having to take summer classes. Believing that she was the cause of Shūsuke's grade for calling him out each …

Shūsuke goes to a Matsuri festival with Nao and Iroha, who compete with each other to try and seduce him. Meanwhile, the A.G.E Explorers go on a quest to find a legendary pornographic treasure and proceed to drag Shūsuke away to join them.…

Late on night, Shūsuke spots a sexy cosplayer named Ran Yatagai on top of a vending machine. He later sees Ran, who calls herself Princess Leila, at school the next day, who invites him and his friends to the rooftop. She claims to be seek…

As Shūsuke puts up with more of Ran's dubious rituals, Rin forces Nao to hang out with her by threatening to tell Shūsuke that she had been stalking him, looking for an opportunity to kiss her. Shūsuke and Nao soon become paranoid around e…

Shusuke and Nao are left alone in the house when their parents go on an overnight trip. Nao takes the opportunity to try and seduce Shusuke by wearing a maid's outfit as he tries to prepare dinner. After washing up after a little accident …