Episodes

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 doing things such as letting him purposely look underneath her skirt (and once letting him see her completely naked) but then she always gets him into trouble afterward so as to make it look like Shūsuke is the immoral pervert. One day, while Nao searches through Shūsuke's room for his collection of porn magazines, she then finds a hidden family photo album and is surprised to find out that there are no childhood pictures of her in it. After Shūsuke was finished being scolded about his porn collection, Nao confronts her parents, Shūji and Nanaka, about the album. They then tell her the truth: 10 years prior to the story, a car accident killed Nao's real parents and left Nao with memory loss, so Shūsuke insisted that Shūji and Nanaka adopt her into their family where he vowed to care & look after her as his sister. Nao, curiously enough, is more shocked by the fact she and Shūsuke are not actually blood related. At that instance, Nao realizes that a possible intimate relationship with him would be acceptable. Nao then requests Shūji and Nanaka to keep the fact she learned the truth from Shūsuke so that they can retain their sibling status. || Shuusuke Takanashi is a high school student that has started seeing his little sister Nao as a target for his fantasies. However, Nao doesn`t mind this at all... in fact, she loves seeing her brother`s nervous reactions whenever she encourages his perverted behavior by giving him a glimpse of her panties, or clinging to him all the time... all while pretending to just be a good little sister. One day Nao sneaks into Shuusuke`s room on the pretense of cleaning it up, but instead goes to take a look at all of his naughty magazines... but she also finds something she never expected to come across...

Nao briefly spots a twin-tailed girl, similar to what appeared in Shūsuke's photo album. At school that day, a girl named Iroha Tsuchiura joins Nao's class and makes friends with Nao. Iroha later comes to Shūsuke, reintroducing herself as his childhood friend and kisses him, proclaiming they are lovers due to games of Doctor they played when they were young. Shūsuke feels ashamed of his past perversion, throwing away all his porn and his perverted nature, which causes Nao to grow concerned. Meanwhile, Shūsuke becomes increasingly worried that Iroha seems to know everything about his private life, and later she blackmails him with threats of telling Nao about their games of Doctor. || 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 her and Shuusuke. The next day, a new student named Iroha transfers into Nao`s class. At first Nao gets along with her really well, and they even end up having lunch together... but while they are eating Shuusuke comes to give Nao her keys which she left at home. Even though Iroha and Shuusuke should be meeting each other for the first time, Iroha seems strangely interested in him...

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 store. At the end of the date, Iroha tries to get Shūsuke to kiss her, but he refuses. Iroha tries to drag him somewhere else, but Nao manages to bail him out. Nao begins treating Shūsuke coldly, leading him to realize that she knew about his date with Iroha. When Iroha scares Shūsuke with the notion that she knows everything he's been doing (having been watching him through a telescope), Shūsuke rolls on the floor when Nao enters, getting a look at her panties which reawakens his normal perversion, much to Nao's delight. || Although Shuusuke didn`t remember her at first, it turns out that Iroha is Shuusuke`s childhood friend - and she knows about all of his dirty secrets. Shuusuke is blackmailed into going on a date with Iroha, although he isn`t actually very keen on going. Nao realizes something fishy is going on, so she decides to follow him when he leaves the house and soon finds out that he is going on a date with Iroha. She decides to quietly stalk the two of them to see what happens between them. Iroha takes Shuusuke all over the place and keeps getting bolder and bolder as the date progresses - eventually she even asks Shuusuke to help her put a swimsuit on. However she isn`t going to let it end with just that - as their date comes to a close, she invites him to do even more naughty things with her... but how is Nao going to react to hearing that?

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 each other for Shūsuke's attention, though it tends to just bring him pain. Nao accidentally knocks him unconscious with a rented boat, and he dreams of his favorite eroge character. Nao and Iroha compete with each other over who gets to perform mouth to mouth resuscitation, though in the end, he is revived by one of his male friends. || The summer heat is unbearable, so Nao decides to ask Shuusuke to take her to the beach so they can cool off by the ocean. At first Shuusuke doesn`t seem too keen on the idea but after Nao hints that she knows about Shuusuke`s date with Iroha, Shuusuke quickly begs his mother for some money so that he can take Nao. But when they arrive they find out they`re not alone - Haruka and Hirono are also spending the day at the beach, and they have invited Iroha to join them as well. An unspoken battle between sister and childhood friend begins as the two girls fight over who should be with Shuusuke.

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 Mister X, discovers about the mix up, he sends Shūsuke a threatening note demanding its return. That night, when Shūsuke attempts to make an exchange with Mister X using a different BL magazine, with Nao and Iroha stalking him, he learns Mister X's true identity is that of his class rep, Mayuka Kondō. With the threat of his porn being shredded or shown to Nao, Shūsuke agrees to become Mayuka's pet, assuming there will be sexual requests involved. The requests start simple, such as buying her a drink or trying her bentō lunch. However, the next evening, Mayuka asks Shūsuke to buy her a more extreme BL magazine she's too embarrassed to buy herself. || Shuusuke sneaks out in the dead of night to pick up a naughty magazine, but on the way home he bumps into a mysterious person wearing a hood. Shuusuke apologizes to the person and quickly rushes home to enjoy his new treasure... but finds his new treasure has changed into a boy`s love magazine instead of the magazine he bought. He realizes he must have accidentally swapped packages when he bumped into the mysterious person, so he tears the magazine to pieces in protest. Meanwhile the mysterious hooded character is just as upset that the boy`s love magazine has been replaced by cute girls in naughty clothes... The next day, Shuusuke finds a blackmail message inside his shoe locker from someone named `Mister X`. It seems Mister X is the mysterious person he bumped into... and he wants to meet with him and exchange magazines. Shuusuke panics when he realizes that he already ripped up the boy`s love magazine, and in his panic he bumps into the student council president - Mayuka... which also lets him get a nice look at her black stockings and panties...

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 what Nao and Iroha see in a pervert like Shūsuke, mentioning her affection towards him is different from theirs. Later that night, Mayuka gets Shūsuke to read through one of her BL books, which ends up traumatizing him. || Shuusuke has discovered that Mister X is actually the student council president - Mayuka, and thanks to her Shuusuke has developed a brand new fetish - a fetish for black stockings... and he`ll even go so far as to become her pet and go out to buy Boy`s Love magazines for her, as long as he can get some glimpses of the panties beneath her stockings. Nao and Iroha start to feel threatened by the relationship between Shuusuke and Mayuka, so they make use of his new fetish to try and lure him back to them... they both sneak into his bed wearing black stockings while he is still sleeping... but what will happen when Mayuka finds out?

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 night, Mayuka feels guilty and offers to help him study for an upcoming exam. But while they were studying, Nao and Iroha decide to intrude on them. As Mayuka tries to get Shūsuke to study, Nao and Iroha compete to try and catch his attention. After some time later, Iroha presents surprise tickets for everyone to go to a local pool park if he passed, which encourages Shūsuke enough to pass. At the pool, Shūsuke spends most of his time teaching Mayuka how to swim, leaving Nao and Iroha pretty jealous. During that time, Mayuka becomes amorously focused with Shusuke's nipples, having never seen a man naked before. As Nao tries to press Mayuka on her attraction to Shūsuke, he nearly drowns after Iroha forces him on a water slide, but is revived thanks to Mayuka's 'cardiac massage'. Afterwards, Mayuka leaves Shūsuke a large list of BL books to buy while she is on holiday. || Shuusuke continues to go out and buy magazines every night for Mayuka which causes him to fail all his subjects due to lack of studying. When Mayuka finds out about this, she organizes to visit him so she can help with his studies... but Iroha and Nao won`t just let her get away with more time alone with Shuusuke... so they decide to `help out` as well. While they are studying Iroha invites Shuusuke to a day at the pool, but Nao notices the tickets Iroha has will let both her and Mayuka go as well. All four head to the pool for a day of fun in the sun... swimsuits included!

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. However, the treasure they find contains zoophillic porn that proves too intense for them and they run away, with Shūsuke picking up Nao in tow. After watching the fireworks with Nao, Shūsuke goes to deliver some BL books to Mayuka, who once again becomes enthralled by his nipples. || Nao visits Shuusuke`s room wearing a yukata and asks if Shuusuke will take her to the Summer festival that is taking place that evening. At first Shuusuke seems hesitant as he doesn`t really have the money to go to a festival... but he simply can`t say no after Nao hints that she isn`t wearing anything underneath her yukata... so he once again begs his mother for a loan and accepts Nao`s request. As Shuusuke and Nao are leaving for the festival they bump into Iroha at the entrance to the house. She is also wearing a beautiful yukata and asks if she can accompany them to the festival, so the three of them head to the festival together. The other AGE members are also at the festival, but they seem to have another goal in mind for the evening...

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 seeking a saviour amongst the scum of the Earth in order to defend it, with Shūsuke and friends believe to be initiation for some kind of underground club. As Nao and Iroha decide to follow her, they meet her twin sister, Rin, who reveals Ran is using her own peculiar method to find a partner. While Rin manages to scare off the other AGE explorers, Shūsuke goes alone to an 'awakening ceremony'. Shūsuke is scared off by Nao's presence and runs off with Ran, who decides he is her saviour. Meanwhile, Rin appears and shows romantic interest in Nao, now that Ran is preoccupied. || On the way home from the convenience store late one night, Shuusuke meets a girl dressed in a rather risque outfit. The next day while he is reporting his find to the other AGE members, he finds out that the girl is actually a student at his school, and she leaves them a message telling them to meet her on the school`s rooftop once school is over. The girl he met is in fact Ran Yatagai, a famous cosplayer who goes by the name `Princess Leiya`. When Shuusuke and the others meet her after school, she tells them that they are candidates to become the savior of the world with her. The boys believes this might let them see Ran in some more erotic cosplay, so they play along with her. Nao, of course, has been quietly watching the whole thing unfold...

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 each other when they see each other hanging around the respective Yatagai sister. Nao and Iroha determine that the only way to get Rin off her back is to convince Ran that Shūsuke isn't her saviour by pretending to be prophets on their mobile phones. Rin catches onto their plan and tries to get the drop on Nao but ends up kissing Iroha instead, though she immediately takes a liking to her lips and runs off with her. Ran later explains to Nao that she wanted to mentally train Shūsuke to play as a warrior for a cosplay event, though when the day of the event arrives, Shūsuke gets the address wrong and arrested for wearing his skimpy outfit in public. || Shuusuke has been selected by Ran as the savior and is hard at work practicing to speak and act like a savior as he has been told he will be revealed as such in just two days time. On the other hand, Ran`s twin sister Rin has become strangely fond of Nao`s lips, and threatens to tell Shuusuke about Nao`s stalking if she doesn`t join her for lunch. Nao eventually asks Iroha for help getting away from Rin... but it might not work out just as planned...

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 in the kitchen, the two become paranoid when Nao starts hearing strange panting, which turns out to be the AGE Explorers, who invite Shusuke out on an unsuccessful search for porn, which gives him a cold. As Nao tends to it, Iroha and Mayuka pay a visit, which once again turns into a battle for his attention. || Shuusuke and Nao`s parents go out for the night, leaving the two siblings at home alone. Nao decides this is a once in a lifetime opportunity and starts to appeal to Shuusuke in every way she possibly can - including dressing up in a cute maid costume while Shuusuke is preparing dinner. But it doesn`t all turn out for the best - Shuusuke ends up knocking over a bowl of mayonnaise and the two end up a complete mess. They rush to the bathroom to get cleaned up, where Nao asks Shuusuke to undo the zip on the back of her maid outfit... but Shuusuke is simply too nervous to do it... Just how will the rest of the night unfold for the two of them...?