* AdaptationDisplacement: Many viewers of the anime have no idea it was based on a series of light novels; some people also assume that the anime is based on the official DatingSim, when the game is actually based on the novels as well.
* BaseBreakingCharacter: First impressions, you can't blame anyone in thinking that Taro Yamada is the most annoying character in the anime series, from making up things to make him look good and his off-putting interest towards the sisters, Taro's antics makes some viewers groan in disbelief. And at the same time, Taro is appreciated as one of the funniest acts in the anime series and being voiced by {{Creator/Kappei Yamaguchi}} helps a little bit.
* DesignatedVillain: [[spoiler: Akio]] doesn't really do much at all, let alone anything villainous, but he's treated as such after the WhamEpisode because he separates Wataru from his sisters.
* EnsembleDarkhorse:
** Mami is pretty popular considering that [[spoiler: she's not really one of the sisters.]]
** Michael, Marie's dog, is adored by everyone.
* HoYay: With Wataru's regular emails to Akio and how he lights up after receiving a reply, and Akio convincing Wataru to return with him - which includes a WallPinOfLove with {{Sexophone}} accompaniment - [[spoiler:not to mention his reaction when Wataru returns to the Island]], Akio's status as the GayOption is apparent.
* IncestYayShipping: Given the nature of the work, this is not surprising. Fans pretty much ship Wataru with almost every one of his sisters, even the youngest...
* OnceOriginalNowCommon: Due to being one of the earliest harem stories in the anime industry, as well as being one that would be a major basis for things like the LittleSisterHeroine boom in the years to follow, it definitely comes across as a massive ClicheStorm that can't really hold up to many of the newer series out there.
* OneSceneWonder: The Mysterious Man in Aria's ADayInTheLimelight episode is fondly remembered as one of the few supernatural entities to make a presence in the anime. It helps that he is a person that Aria is very fond off outside her older brother and sisters.
* TheScrappy: While he is not hated persay, you'd be hard-pressed to find people who like Minai. This is due to the fact that Minai is nothing more than an undeveloped {{Foil}} to Wataru and his remarks upon Wataru's return is viewing him as nothing more than a rival and an obstacle, disregarding Wataru's genuine friendship for him.
* UnintentionalPeriodPiece: The show's general enthusiasm about and fascination with e-mail pins it firmly to the late nineties and early 2000s. Also, one episode has the girls very excited to have Rinrin's latest technological breakthrough--a handheld device that allows them to send e-mails wirelessly.
----