The Mysterious Boy is a background character who make a cameo in each episode of Ojamajo Doremi Naisho.
Not much is known about the Mysterious Boy's personality, however his facial expressions suggest that he is sad and depressed.
List of Cameos
A Screwed Up Bicycle Trip; The Secret Of The Boys
The Mysterious Boy is seen sitting in the crowd at the beach.
Maho-Dou in New York; Momoko's Secret
The Mysterious Boy is seen in the crowd waiting to their autographs signed.
The Value of Swimming!; Aiko's Secret
The Mysterious Boy is seen sitting at the side of the pool.
Non-standard; Onpu's Secret
The Mysterious Boy is seen with the crowd as they applaud Onpu.
Someone Who Knows the Sorrow; Pop and Hana's Secret
The Mysterious Boy is seen as the students are changing into their school shoes.
Memories in Confeito; Baaya's Secret
The Mysterious Boy's silhouette is seen in the audience.
I Love Taiyaki!; Father and Son's Secret
The Mysterious Boy is seen in the queue outside the Maho-do
Flute File!; An Honor Student's Secret
The Mysterious Boy is seen sitting in the back of a truck.
Excellent Baseball Team ~The Witches' Secret
The Mysterious Boy is seen in the audience as Majorika cheers for the Ojamajos.
Marriage Promise; Childhood Friend's Secret
The Mysterious Boy is seen hiding behind a woman in the newspaper.
Valentine's Day; Hazuki's Secret
The Mysterious Boy is seen in the crowd as Onpu is surprised at the amount of valentine chocolate she received.
The Seventh Witch Apprentice; Non-chan's Secret
The Mysterious Boy is seen sitting on the bench as Doremi is running thought the hospital.
Dolls Through the Ages; Doremi's Secret
The Mysterious Boy is seen walking to school as Onpu is talking to her friends.