The Empty Box and the Zeroth Maria

Utsuro no Hako to Zero no Maria (空ろの箱と零のマリア), also known as Hakomari (箱マリ) for short, is a Japanese light novel series written by Eiji Mikage, with illustrations by Tetsuo. The first volume was released on January 7, 2009. Currently, there are 6 published volumes. All published by MediaWorks under their Dengeki Bunko label.

Plot Synopsis
Hakomari tells the story of Kazuki Hoshino, who is almost madly attached to his everyday life, and his antagonist Aya Otonashi, who suddenly transfers into his class at the end of the school year — for no less than the 13,118th time. Without hesitation, she announces her intent to "break" him.

Kazuki's struggle to defend his everyday life begins, and the many secrets it is built on start to come to light.

Main characters
Kazuki Hoshino (星野 一輝): Kazuki is the protagonist of the Hakomari series. He is a completely ordinary high school student who loves idle chatter with his friends and Umaibōs, a Japanese snack. The story begins when Kazuki is offered a box by O. Kazuki however refuses the box because the only thing that he wishes for is a normal everyday life. Because of Kazuki's disinterest in the box and his will for an everyday life, O becomes interested in Kazuki. O gives boxes to several people around Kazuki, and before Kazuki knows it his everyday is being destroyed in several different ways. O makes it his mission to study Kazuki in these different scenarios until he believes Kazuki will give in and use a box himself. One day, he is suddenly antagonized by Aya Otonashi — although he has never met her before. She threatens to "break" him.

Maria "Aya" Otonashi (音無 麻理亜): Maria is a beautiful but unsociable girl with a resolute personality. She transferred into Kazuki's class on March 2nd — almost at the end of the school year. Maria is very stern in her actions and beliefs. She expressed her wish to "break" Hoshino at the very beginning. There is one however one thing that Maria is terrified of, and that is killing someone else. No matter the circumstance, Maria refuses to kill anyone even if it meant saving Kazuki's life. Maria must care deeply for other people, because of her wish to become a box herself. She is willing to sacrifice her own memories in order to give other people a place where they can be happy inside her box.

Supporting characters
O: O, commonly misread as 0 (zero), is the antagonist of the series and the giver of 'Boxes' that grant wishes. O has a strange curiosity with Kazuki Hoshino which is the source of much of the mayhem within the story.

Kokone Kirino (桐野 心音): Kokone is a bright and beautiful girl who cares a lot for her friends, but is meddlesome at times. She and Daiya have known each other since childhood, and their mutual verbal abuse has become legendary among their classmates ever since. Kokone is a very outgoing person. She likes to tease Kazuki, Haruaki and Daiya, who often tease her back.

Daiya Oomine (大嶺 醍哉): A self-centered and arrogant student who dyes his hair silver and wears three piercings in his right ear. He is the class president of the second year students and a shrewd friend of Kazuki's.

Kasumi Mogi (茂木 霞): Kasumi is the girl who has won Kazuki’s heart. She is docile, silent and expressionless. Kasumi lived a normal life going to school, however she was always depressed. She never showed any emotions herself, she always forced a smile onto her face, and was never happy. Kasumi thought everyone else must be faking it too. She thought nobody would ever notice her, until one day Kazuki ran towards her after she left school. Kazuki asked if she was okay, because she seemed bothered. Mogi denied anything bothering her, but at the same time she fell in love with this Kazuki who noticed that her smile was fake.

Haruaki Usui (臼井 陽明): Haruaki is a cheerful but frivolous baseball ace. He often hangs out with Kazuki and Daiya.