The third film finds Ataru transformed into a pink hippopotamus, which sends Lum chasing after the wicked magician responsible, with catastrophic results. With Lum gone, her friends decide that there is no reason to remain, and so Tomobiki slowly returns to normal. The highlight of the film is a high speed chase scene with an angry Lum flying after the mysterious Ruu through the city at night and into a hall of mirrors (and illusion ). Ataru's true feelings for Lum are probably more obvious in this film than any of the others.

Lupika, an alien princess, is in love with a tofu seller. To make him love her too (at least, announce his love. He obviously fears the social taboo of a tofu vendor marrying a princess), she needs to get a love potion, which is in a certain temple. Legend has it that the only person that can obtain this love potion is the most lecherous man in the universe. That man turns out to be Ataru Moroboshi. Lupika kidnaps Ataru to make him get the potion, and Lum and her friends go out to search for Ataru.

The invasion of an alien race known as the Oni begins a new life for Ataru Moroboshi, a lecherous trouble-making tenth grader in the small town of Tomobiki. After unwittingly proposing to the Oni princess Lum Invader instead of his sweetheart Shinobu, Ataru becomes a conduit for aliens arriving on Earth, causing all sorts of havoc for him and his companions, not to mention his own reputation!

As the perpetually lecherous Ataru and his friends prepare for a carnival at Tomobiki High School, they gradually realize the days are literally repeating themselves. Any effort to break the pattern dumps them back where they started.

Featured special that uses scenes from the series stored on a personal satellite of the Los Mendo family.

It seems that Lum's grandfather made an agreement that should he have a daughter, she would be married to a traveling merchant that he met. Now, the merchant has come to collect due. Ataru is tricked into thinking that Lum wants to leave, and so, in a moment of anger, says he hates her. Arguments erupt, and Lum decides that she must know the truth of Atarus feelings. As for all the questions of importance for the Onis, a game of tag begins, one that Ataru can win simply by telling Lum I Love You. However, in the end his pride may end up dooming him. So begins the series of events that will at long last decide the future and fate of Ataru and Lum.

While performing in a student film, Ataru cuts down Tarozakura, a large, ancient cherry tree. Strange things begin to happen all across Tomobiki: a mountain appears out of nowhere, spring changes to winter, and Lum loses her powers, while those around her act as if she doesn't exist.

Ryoko throws a tea party for her friends. Flashbacks reveal the pasts of Ryoko's various guests.

【STORY】 　　故事以克苏鲁神话为基础，结合恋爱喜剧的情节，原作插图并由负责「我的狐仙女友」插画的狐印所绘画，所以萌元素是相当之高。而情节方面是讲述高中生八坂真寻，在某日晚上忽然间被怪物所袭击，此时出现搭救他的，就是自称克鲁苏神话中旧日支配者之一的银髮美少女「奈亚拉托提 普（暱称为奈亚子）」。身为宇宙人的她是神话中可以自由变化外表的「无貌之神」，由于其它的宇宙人正准备攻击真寻，所以才会被派遣到地球来保护他。 　　【STAFF】 　　原作：逢空万太（『潜行吧！奈亚子』系列　GA文库／Softbank Creative 刊） 　　人物原案：狐印 　　监督：谷东 　　脚本：小早川すすむ、中野守、谷东、逢空万太 　　平面设计：RFV design 　　作画：铃木隆辅、西山司 　　音响监督：はたしょう二 　　音乐：SLF!! 　　动画制作：DLE 　　制作：Softbank Creative 　　【CAST】 　　奈亚子： 阿澄佳奈 　　真寻： 喜多村英梨 　　酷子： 松来未祐 　　阿托子： 片冈梓 　　奈亚惠： 原纱友里 　　【主题曲】 　　『恋爱少女情绪』 　　歌：LISP（阿澄佳奈･片冈梓･原纱友里） 　　作词：池畑伸人･船迫桃代 　　作曲･编曲：大谷靖夫（DIVEⅡentertainment） 　　【官方网站&放送情报】 　　官网链接：http://ga.sbcr.jp/bunko_blog/nyaruani/index.html 　　放送时间：2010年12月10日

【STORY】 　　故事以克苏鲁神话为基础，结合恋爱喜剧的情节，原作插图并由负责「我的狐仙女友」插画的狐印所绘画，所以萌元素是相当之高。而情节方面是讲述高中生八坂真寻，在某日晚上忽然间被怪物所袭击，此时出现搭救他的，就是自称克鲁苏神话中旧日支配者之一的银髮美少女「奈亚拉托提 普（暱称为奈亚子）」。身为宇宙人的她是神话中可以自由变化外表的「无貌之神」，由于其它的宇宙人正准备攻击真寻，所以才会被派遣到地球来保护他。 　　【STAFF】 　　原作：逢空万太（『潜行吧！奈亚子』系列　GA文库／Softbank Creative 刊） 　　人物原案：狐印 　　监督：谷东 　　脚本：小早川すすむ、中野守、谷东、逢空万太 　　平面设计：RFV design 　　作画：铃木隆辅、西山司 　　音响监督：はたしょう二 　　音乐：SLF!! 　　动画制作：DLE 　　制作：Softbank Creative 　　【CAST】 　　奈亚子： 阿澄佳奈 　　真寻： 喜多村英梨 　　酷子： 松来未祐 　　阿托子： 片冈梓 　　奈亚惠： 原纱友里 　　【主题曲】 　　『恋爱少女情绪』 　　歌：LISP（阿澄佳奈･片冈梓･原纱友里） 　　作词：池畑伸人･船迫桃代 　　作曲･编曲：大谷靖夫（DIVEⅡentertainment） 　　【官方网站&放送情报】 　　官网链接：http://ga.sbcr.jp/bunko_blog/nyaruani/index.html 　　放送时间：2010年12月10日