When abandoned kittens and his good conscience force second year Sorata Kanda to move into Suimei High School’s infamous Sakura Hall, the satellite dorm and its eccentric, misfit residents turn his life upside down. The decidedly average Sorata finds it difficult to fit in with the bizarre collection of dorm residents like Misaki, an energetic animator; Jin, a playwright playboy; Ryuunosuke, a reclusive programmer; and Chihiro, the dorm manager, art teacher, and party girl. Sorata's friend Nanami, a second year student and aspiring voice actress, pushes him to find new owners for the many cats so that he can quickly move back into the regular dorms. However, his desire to escape Sakura Hall wavers when the pet-like and infantile second year Mashiro Shiina, a world-class artistic savant looking to become a mangaka, transfers in during the spring trimester and quickly latches onto him. Supported by each other's quirks, Sorata and Mashiro come out of their shells and trigger change in the lives of those around them. Based on the light novel series of the same name, Sakurasou no Pet na Kanojo explores the fine threads connecting talent, hard work, romance, and friendship with its ensemble cast.

Lum doesn't need much assistance going ballistic when everyone in Tomobiki gets an invitation to Ataru's wedding -- and she's not listed as the bride! It seems that some 11 years ago, Ataru played "Shadow Tag" with a young girl named Elle and won. Unfortunately, Elle was yet another Alien Princess; and on her planet, if a boy steps on a girl's shadow, they have to marry. 
When Elle's emissary comes to make arrangements, Lum redefines the term "the atmosphere was electric," but to no avail: a force-field now protects Ataru from her high voltage love-zaps. Lum's friend Benten suggests a pre-emptive wedding, and they proceed to abduct Ataru and all of the wedding guests, and the stage is set for the shotgun wedding of all time!

Not all is normal in Tomobiki, even by its standards. The students have been preparing feverishly for the first day of the student fair, which is scheduled to go on the next day. However, problems arise when some begin to notice that the next day simply will not come. As the students begin to try to find the reason for the problem, their beliefs about reality and the world of dreams are challenged.

It seems that when Lum was born, a postal screwup resulted in a witchy friend of the family not getting an invitation to the celebration. The witch put a curse on Lum, that she would never be happy with her True Love. 

In the present, a new Amusement Park has been built in Tomobiki, and opening day finds the whole gang sampling its pleasures. At a magic show, however, Ataru gets turned into a large pink hippo-potamus, FOR REAL! 

When Lum attempts to track down the magician that transformed her Darling, things start to get very weird, very fast! 

(Source: AniDB)