Teacher Sorata Muon carries on his family's centuries-old old tradition of being the master thief Mouse who can steal anything after properly alerting authorities of his intentions so they can be there yet fail to stop him. He is assisted by 3 nubile female assistants who also use the teaching cover and who, in typical Satoru Akahori, favor tight/skimpy/bondage outfits over their ample curves as they constantly pursue Sorata much more than he pursues them, although the girls do get some attention from their master. Not only is Mouse pursued by the girls & the local law enforcement authorities, there is also a secret art protection society employing the services of a former ally of Sorata's after his pretty little hide, all in 15 minute episodes.

Shouta Handa is a jobless 25 year old who is sick and tired of his boring life. One evening, at the class reunion, he gets to meet all of the cute girls that used to be his classmates. He soon discovers that they are all successful with interesting careers, and even more importantly—really beautiful now, with bigger curves. Unfortunately, it seems that they are all aware of his boring, unsuccessful life, so they mock him and call him a loser, just like in the old days. Everything changes when Shouta goes for a walk to have a smoke and accidentally falls into the school swimming pool. This triggers a supernatural phenomenon that takes him back ten years into the past. He finds himself in the same swimming pool during swimming class, surrounded by his female classmates in bikinis. How is Shouta going to deal with their cuteness and closeness now that he is a grown man in a boy's body?

Seton Academy is a place attended by a plethora of interesting and diverse animal species. Jin Mazama is one of the few humans there, who also happens to vehemently hate animals from the bottom of his heart! One day, he stumbles upon the rowdy and assertive girl Ranka Ookami, a small lone wolf without a pack, who has not a single friend. The desperate Ranka tries to invite Jin into joining her pack; Jin, who hates animals, naturally refuses. Amid this situation, Jin meets Hitomi Hino, a fellow human, and promptly becomes infatuated with her. After getting to know each other, the two decide to create a cooking club, and after a few bad-blooded misunderstandings, Ranka soon joins the club as well. Thus begins the howl-some and howl-arious story of two normal humans; an adorable wolf; a cheerful koala; a sluggish, blonde sloth; and a feline with cattitude in their newfound club—in a story that teaches that friendship can be forged by creatures of different kinds.

A special unaired episode of Musaigen no Phantom World bundled with the series' seventh DVD/BD volume.