Story:

Our story follows Kanoue Yuuma, an amnesiac boy with a special power, and Nikaidou Shinku, a translucent girl only visible to Yuuma who gave him that power. With it, he can heal any and all wounds.
But it comes at the cost of the memories he's made.
He lives a simple life: going to school and being scolded by his childhood friend, Kisaragi Mio, by day, and working with his master, Natsume Suzu, in the evenings.
However, whenever he falls asleep, he always sees the same dream... a white world, feathers falling, and a girl calling out for him to save her.
The student dormitory his master resides in has a special door in the basement, which connects their world to a myriad of different parallel ones. He travels from world to world, searching for one that resembles the scenery he sees in his dreams, but to no avail.

Then, one night, as he's out at night strolling around town, he spots a girl jumping from the lighthouse.
Yuuma rushes over and heals her using his power, but after coming to, the girl claims to know him and his power, and asks him much like the voice in his dreams:

"Please save me, Kanoue Yuuma."

Characters:

Nikaidou Shinku:

The translucent sorceress who gave Yuuma his special power.
A calm, rational girl who rarely shows her emotions. She exudes an air of maturity in stark contrast to her youthful appearance.
She currently sticks by Yuuma's side to achieve a certain goal--that is, to get him to experience love.
"Love. Romantic feelings. I want you to experience the one thing I was never able to."

Minami Kana:

A strange, unknown girl who fell from the sky one night.
After Yuuma managed to save her, she claimed to have known him and exchanged a certain "promise" with him many years ago, which he has no recollection of.
Eventually, she comes to live alongside him in the dormitory, taking it upon herself to perform the duties of a maid.
While she's able to take care of household chores, her cooking is abysmal, and she seems to be gravely lacking in the common sense department.
"Please, help me, Mister Sorcerer. I'm really in quite the predicament right now!"

Kisaragi Mio:

Yuuma's childhood friend, who's in his class at school.
Due to their longstanding friendship, teachers and other classmates often come to her for all matters concerning Yuuma, the habitual skipper, which slightly peeves her.
She's noticed Yuuma getting chummy with a lot of girls who (she thinks) are cuter than her, which has secretly been a source of stress for her.
Her cooking skills are excellent, as are her domestic skills in general.
"That's what I like about you. You're sincere."

Shikishima Kyou:

A looney girl with an imaginative mind who never leaves her room in Arashiyama Hall and loves spouting off her delusions of grandeur.
She has a very laid-back demeanor, and despite being a slight airhead, doesn't hold her punches when it comes to criticism.
Due to being a social outcast who lives day in and day out playing and watching nothing but games and anime, she never sees the light of the sun, and accordingly, her skin is fair and white.
Being a night owl, she always seems sleepy, but ever since meeting Yuuma, she's been leaving her room more and more.
She also seems to possess a mysterious power...
"Are you my brother?"

Toumine Tsukasa:

A new resident at the dorm who always seems to be running to and fro, busy as a bee.
She's a grade below Yuuma at school, and to pay for her tuition and living expenses, she works until late at night at the local bathhouse.
She's honest to a fault and hard-working, but also very stubborn. Once something gets into her head, it can be hard to convince her otherwise.
She also has a habit of tripping over nothing, although that isn't to say she's clumsy in general.
She can handle household chores with ease and excels in particular at doing menial tasks.
"The local baker man is a god incarnate!"

Reviews of Irotoridori No Sekai - The Colorful World