The Light Novel series is the source material for the adaptation of the Anime and Manga series. The information and terminology on the article will be based on the source material rather than the adaptions.
Despite being heavily pushed to become the next Aub Drewanchel, Ortwin himself would much rather leave the title to his half-siblings and dedicate his life to research. He he finds it very difficult to disobey his sister and thus works diligently on achieving the excellence expected of the next archduke.
Once Rozemyne returns to the Royal Academy, Ehrenfest sends out invitations to all duchies for a final tea party before the Interduchy Tournament. Due to a limit on the number of people they can accommodate, they ask that each duchy only send one person (and their retainers) to attend. Ortwin is eager to go to the tea party; however, his sister Adolphine claims the spot for herself.
After the tea party Adolphine hands Ortwin a small jar which contains a sample of a substance called Rinsham, which makes a person's hair smooth and lusterous when washed with it. She asks him to analyze it over the rest of the year and come up with their own version of it before the next winter. While Ortwin is not interested in the beauty aspect of it, he is intrigued for scientific reasons. Over the course of the year he is partially successful in creation a derivate of Rinsham, but isn't able to reach the same level of quality as the original. While his product does much the same as original Rinsham, it does not make the hair quite as glossy and silky as the original. It is also slightly unpleasant to the scalp when used, according to Adolphine.
In the following term at the academy, Ortwin and Wilfried share a very enthusiastic greeting and promise each other to meet and play gewinnen again, hinting that they have formed a friendship while Rozemyne was absent from the academy the previous year.
When Adolphine borrowed books from Rozemyne, Ortwin also read them. He quite enjoyed them, but is getting rather tired of only ever getting to read the romance stories his sister borrows. At the a tea-party with Rozemyne however, the Ehrenfest archduke candidate promised she would lend Ortwin a book with knight's stories through Wilfried.
- Ortwin had an unnamed cameo during the court etiquette class in Part 4 Volume 1, in which he was admonished for keep talking about himself.
- Ortwin's Gewinnen figures, which were a gift from his father, are coloured red, like his hair and eyes.
- Ortwin is consistently beaten by his sister Adolphine in gewinnen. But he is able to beat his friend Wilfried most of the time. He considers Daividh to be an easy mark in the game. He also has not lost a single match against Konradin, but strongly suspects that Konradin let him win to not stand out due to their respective statuses, their duchy's ranks and being the son of a third wife.
- Ascendance of a Bookworm. Part 4 Volume 3. Chapter 11: The Tea Party for All Duchies
- Ascendance of a Bookworm. Royal Academy Stories - First Year. Chapter 15: Ortwin - The Drewanchel Siblings
- Ascendance of a Bookworm. Part 4 Volume 5. Chapter 18: The Second-Year Fellowship Gathering
- Ascendance of a Bookworm. Part 4 Volume 7. Chapter 10: Tea Party with Drewanchel
- Ascendance of a Bookworm. Royal Academy Stories - First Year. Chapter 11: Wilfried - Male Socializing