A year ago, Hiccup received a letter from Hogwarts, saying that he was a wizard, but he refused for the sake of his father's affirmation and the recognition of his clan. Another year, the same time as last year, Hiccup received a letter again, and this time in order to avoid Toothless being discovered, Hiccup decided to go there.
It is said to be about training a dragon + HP, but in fact it should only be about HP. The plot of how to train a dragon will not appear in the text. If you haven't watched How to Train Your Dragon, you can check it out. Hiccup and Toothless are both cute, and there may be a story about how to train your dragon in the extras.
It is set that Hiccup meets Toothless when he is 12 years old, the Red Death incident has not happened yet, and he is directly entering the second grade.
HP sub-era is at the same level as Harry Potter, Harry Potter is reborn, CP Hadha