All-boys school where some guys randomly turn into girls for a temporary amount of time throughout the day because puberty.

Original Pixiv Comic:

Recently, Hama Konpachi has been having nightmares about a ribbon growing out of his chest. That's not to mention all the strangers who mistake him for a girl, and the nickname "princess" that his classmates use. His childhood friend Shintarou says he worries too much about his femininity, but Konpachi just can't abandon his wish. "I need to become a big, strong boy as soon as possible!"... more>>

But then one day, he's pulled into a strange book in the library and meets Marianne, the self proclaimed "strongest witch in history." She makes him an offer. "Will you become my pupil?" Magic is something that can only be used by "maidens," but somehow the male Konpachi has the potential?

But before Marianne can finish speaking, that ribbon from his dream begins growing and wraps Konpachi up! And when the ribbon comes undone, Konpachi has become... a girl?

Can Konpachi use his feminization magic to escape from the Vignette in this gender-bending fantasy story? <<less