Plot/Story
A typical boy, Rito, is struggling to confess to his crush, Haruna. Never gaining enough courage to actually do the deed, he forever watches from the sidelines... Until an alien girl, Lala, a Princess from the planet Deviluke appears before him, on the run from someone! With Rito's help, they manage to allow Lala to stay on Earth. However, when Rito finally gathers his courage to confess to Haruna, Lala is there instead, and she accepts. Haruna, who had always secretly loved Rito, witnessed this and shows no reaction to Rito's dismay. Now Lala, who now loves Rito, thinks they are engaged, and to make matters worse, she transfers into his school. With plenty of room for misunderstandings, from Lala and Rito falling out of a locker naked, in front of Haruna; different marriage candidates for Lala who try to kidnap her; a assassin hired to kill Rito, but instead becomes best friends with his sister; Ren, a prince from the Memorze planet, madly in love with Lala and hates Rito, who hold the ability to change gender; and more and more girls being dragged in, who fall in love with Rito (like Yui, an uptight girl; Lala's twin sisters Nana and Mom; Run, the female Ren, one of the many reasons why Ren hates Rito). With girls overflowing, and misunderstandings as rife as the air, this manga is the king of all Harem-Ecchi mangas.

Characters
Each character are unique, and vital to the story, in their own way.

Rito - An ordinary boy with A simple crush for his classmate Haruna, until he meets Lala. He has extreme bad luck, is extremely clumsy, and always manages to make misunderstandings. Lives with his little sister Mikan, while their parents are away (Mother a famous fashion designer in France, while Father a Mangaka in his studio).

Lala - The main (?) heroine, an alien princess. She loves to invent things which always cause trouble for Rito. An important invention was Peke, a clothing robot who always clothes Lala, until she wears normal clothes. She has a tail, which is her weak spot, causing her to loose all her energy. Her mother was said to be one of the most beautiful sentient beings in the galaxy.

Haruna - The other main (?) heroine. Has always loved Rito, but has never been able to talk to him, nevermind confess, until Lala comes. Lives with her older sister Akiho and her dog.

Ren and Run - The two personalities of the one body they share. They have known Lala since childhood, but while Ren loves her, Run hates Lala, and while Run loves Rito, Ren hates him. The change in his/her gender can be caused by a sneeze.

Yami (Golden Darkness) - The assassin hired by one of Lala's fiancé candidates to kill Rito, but fails and ends up watching him to "look for the perfect opening". Becomes best friends with Rito's sister, Mikan. Loves taiyaki, as it was the first food she ate on Earth (coincidently given to her by Rito). Hates Ecchi people (Rito).

Yui Kotegawa - A self-righteous classmate of Rito, Lala and Haruna. She hates 'unacceplable behaviour' which is mainly from Rito, but later it is discovered she starts to desire Rito to do things like that to her. Has an older brother, Yuu Kotegawa, who thinks she is dating Rito.

Mikan - Rito's younger sister, she does most of the housework. Loves her brother, friends with Yami, very knowledgeable about what Rito is thinking. Was at first surprised, but is now used to Lala being naked next to Rito in the mornings.

Nana and Momo - The younger twin sisters of Lala, Nana can talk to animals while Momo can talk to plants. Nana has a flat chest, the only flat chest in her family. Momo has a sweet personality, but becomes dark when Nana takes credit from things she does.

Celine - A plant Rito got from Lala on his birthday, which later changes to a human when the plant dies. She becomes a small girl, and some people think that it is Rito's and whoever he is with (usually Yui) daughter. Has a flower on her head that, when she gets drunk from Coke, spits pollen which causes people who get it fall in love with Rito.

Kenichi - Rito's best friend who falls in love with Riko (Rito who had his gender changed by an invention by Lala). He is basically a pervert.

Saki - The self proclaimed "queen" of the school, he is incredibly jealous of Lala because she had a fiancé, but the the person who she was in love with is the guard of Lala.

There were other characters, but these are the main bunch...

Drawing Style
The drawing style was cartoon-like, which suited the theme of it being gag-like very well. The characters suited their design, and the inventions suited the cartoon-like drawings.

Enjoyment
This was extremely enjoyable, not very repetitive, and very fun to read. It did start to feel reused, but then new characters, inventions or situations were added, enough to just tweak the story ever so slightly while it being the same, nothing being conjured from nothing (well, nothing more then usuall).

Overall
Overall, even with the recycled story, more characters then the city of London and the cartoon-like drawing style, it was a good read. The winning point, for me anyway, was the fact that both the Harem and Ecchi elements were very well done, and the Harem consisted of more then just three girls like they usuall do, but about fifty girls. The main character, Rito's clumsiness, perfected the misunderstandings of the Ecchi element. Lala's straight-forward personality made certain situations worse, and her somewhat innocent actions caused problems too. Each character reacted in ways that they should, some not bothered (like Lala) while others were extremely embarrassed (like Yui and Haruna).

All in all, great for a time-consuming relaxing read, with little to no angst, drama or worry. It was just a gag-filled fun manga.