Can you recommend some similar light novels like 'At Night I Become a Monster'?

One book that might be similar is 'The Monstrumologist'. It also involves elements of the strange and monstrous. Another could be 'Miss Peregrine's Home for Peculiar Children' which has a touch of the abnormal and mysterious like your mentioned novel.

One similar light novel could be 'My Youth Romantic Comedy Is Wrong, As I Expected'. It also has complex characters and an engaging plot. Another is 'Re:Zero − Starting Life in Another World', which has a unique take on the isekai genre like 'Sweetest Monster Light Novel' might. And 'The Rising of the Shield Hero' is also a great choice with its own interesting world - building and character development.

Another option is 'Ascendance of a Bookworm'. The main character has to navigate a new world and rise in status, which has some parallels to the idea of becoming a queen in 'I shall become the queen light novel'. It's a great read for those who like the genre.

One similar light novel could be 'Another'. It also has a somewhat dark and mysterious atmosphere with unexpected twists and turns in the plot.

Well, 'Kuma Kuma Kuma Bear' might be something you'd like if you enjoy 'Monster Duchess and Contract Princess'. The main character has to navigate a new world and deal with various situations. Also, 'The Saint's Magic Power is Omnipotent' is similar in the sense that it has a female lead with special circumstances in a new environment, and there are elements of magic and unique relationships like in the 'Monster Duchess and Contract Princess' light novel.

The concept of becoming a monster at night is really captivating. It creates a sense of mystery and dual identity. The main character has to deal with this secret side of themselves, which adds a lot of depth to the story.

Well, 'Ascendance of a Bookworm' has some similarities. The main character in that light novel has to build her own 'stardom' in a sense within the world of books and knowledge, which is different from but related to the journey of the character in 'I am a Superstar'. Also, 'KonoSuba' has a protagonist who becomes well - known in his own strange way in a fantasy world, much like how the character in 'I am a Superstar' might gain fame in their respective setting.

One similar light novel could be 'Overlord'. It also features a protagonist in a powerful position, much like in 'I'm the King Light Novel'.

One similar light novel could be 'Sword Art Online'. It also has a unique world - building and engaging characters. Another one is 'Overlord', which shares the theme of a powerful protagonist in a different kind of world.

One similar light novel is 'Battle Through the Heavens'. The story follows the main character's path of self - improvement and achieving a high - level status, much like the concept in 'I am supreme light novel'. And 'Desolate Era' also has a story that involves the main character's rise to power and supremacy.