Ojamajo Doremi 16 is a spin-off light novel series restarting the Ojamajo Doremi franchise, now focusing on the original casts' high school lives.

Doremi Harukaze, a 10th grade student! Today is my elementary school reunion. I should meet Hazuki-chan, Ai-chan, and everyone else, but Onpu-chan isn't here...

What happened to her? Also, when I try going back to the place of my memories, somehow, the MAHO Dou is there. And now, why is Majorika even here?! I generally have a probable bad feeling about this. Can I become a witch apprentice again? Will I become one? What should I do?!

In this Ojamajo Doremi, everyone has turned 16 years old and came back!!

(Source: Ojamajo Doremi Wiki)