Liam Scholes, 11, caused a stir when he arrived at Sale High School in Trafford, Greater Manchester dressed as the erotic novel’s male protagonist, Christian Grey.
The boy, who was wearing a suit and carrying cable ties and an eye mask, had to alter his outfit before he was allowed to take part in events to mark the annual celebration of reading.
Head teacher Lynn Nicholls said: “The school stands by the decision it made in relation to the costume worn by one of its students to World Book Day.
“The decision reflects the school’s high standards in terms of student behaviour, welfare, and safeguarding.
“The student was not excluded from taking part in any of the activities, as has been wrongly reported. His costume was modified and he was then able to fully participate and enjoy the day with his peers.
“The aim of our World Book Day events was to celebrate and encourage reading and we are disappointed that what was a fantastic day for our students has been marred by this issue.”
The school marked World Book Day by asking pupils to dress as literary characters.
Liam’s mother, Nicola Scholes, 36, said: “I don’t regret allowing him to go as that character.
“He’s a character that has been put out there on the television and all aspects of media.
“Every child at the age of 11 knows who he was. He walked into school and every child knew who he was.
“I don’t think he’s gone as something that has not been accessible to children of his age before.”
offensive costume.Excluded from photos, told to change yet teacher dressed as a serial killer and others with guns? pic.twitter.com/8OTZ9gPvEh— nicola scholes (@clangar) March 5, 2015
Liam said: “He’s the character that has been talked about the most in the past few years and he’s just been everywhere you go.
“I think it’s the content of the book that might [make] people think that it’s inappropriate. But I went into school as Christian Grey just for a laugh, not anything else.”
A film based on the book by EL James — which has sold more than 100m copies worldwide — hit screens last month.
Campaigners claim the story of billionaire Christian Grey’s relationship with Anastasia Steele promotes domestic abuse.