The Kusaribe family is a family of sorcerers under the protection of the ‘Tree of Origins.’ Their princess, Hakaze Kusaribe, was the greatest sorceress of their family. But Samon Kusaribe, a member of their family seeking to resurrect the ‘Tree of World's End,’ a tree that opposes the ‘Tree of Origins’ and controls the power of destruction, stuffs her into a barrel, and banishes her to a deserted island.

春假结束，料峭时节，南家三姐妹妙趣横生的小故事继续上演。散发圣母光芒的大姐春香（佐藤利奈 配音）继续照顾一家人的起居，当然时不时会懒病爆发；最大笑果夏奈（井上麻里奈 配音）在犯傻卖萌的路上高歌猛进，与藤冈（柿原徹也 配音）、理子（高梁碧 配音）以及姐妹闹出不少的笑话；看似不在乎周围一切实则冷静观察众人的千秋（茅原实里 配音），其吐槽功夫日渐纯熟，或者一言不发，或者一语惊人。从清爽的春天到炎热的夏天，朝气蓬勃，青春活力，呆萌的小姐们如约而至……
本片根据樱场小春的同名漫画改编，是该系列动画的第四季。

It is August 12th. After the remote control to his boarding house's only air conditioning unit is inadvertently destroyed by spilled cola, "I" devises a plan to return to yesterday in a time machine to recover the remote before it breaks. However, his prankster friend Ozu cannot resist playing with past events, even if it means bringing the universe to the brink of destruction. Now "I" finds himself racing through time to avoid disaster.

Shinichi Chiaki is a first class musician whose dream is to play among the elites in Europe. Coming from a distinguished family, he is an infamous perfectionist; not only is he highly critical of himself, but of others as well. The only thing stopping Chiaki from leaving for Europe is his fear of flying. As a result, he's grounded in Japan.

During his 4th year at Japan's top music university, Chiaki happens to meet Noda Megumi—or as she refers to herself, Nodame. On the surface, she seems to be an unkempt girl with no direction in life. However, when Chiaki hears Nodame play the piano for the first time, he is in awe at the kind of music she plays. To Chiaki's dismay, Nodame moves into the apartment next to his and finds out that she is head-over-heels in love with him.

Three problem children - Izayoi Sakamaki, Asuka Kudou, and You Kasukabe - suddenly receive an invitation to another world known as "Little Garden" from a girl called Black Rabbit. Battles, laughter, sex appeal... anything goes in this new tale of adventure!

When a college dropout stops for a late night bite at a mysterious ramen stand, he crosses paths with a self-proclaimed deity of matrimony. This bizarre meeting sends the young man hurtling through a horrifying flashback to his not-so-glorious college days when the influence of a cruel new friend turned him from a hopeless romantic into a mischievous “black cupid.”