One great Lovely Complex fanfic is 'A New Beginning' which explores an alternate universe where the characters meet in a different setting. It's really interesting to see how their relationships develop in this new scenario.
First, really understand the characters. Read the original work carefully to get their personalities, quirks, and relationships. For example, Risa's insecurities about her height and Otani's complex about being short are important aspects. Then, come up with an interesting plot. It could be something like a new event in their school life or a different way their relationship could develop.
There were many anime or manga that had a brother complex that could be referred to as the following popular works:
Naruto: It tells the story of a ninja village where there is a strong familial relationship between the brother and the younger brother.
2. The Attack of the Giant: It tells the story of human survival under the attack of giants. There is also a complicated relationship between the brother and the younger brother.
3. Inuyasha: It tells the story of an ancient Japanese monster world. There is also a strong kinship between the brother and the younger brother.
Slam Dunk: It tells the story of friendship and kinship between basketball players. The brother and brother are also closely related.
5. Silver Soul: It was about a funny, spoof, and nonsensical anime. The brother and brother also had a funny relationship.
All of the above works had the element of brother control or brother control. You can choose to watch them according to your preferences.
The recommended novel was,"He Spoiled the Little Ancestor to Death." The novel was a modern romance novel about wealthy families. The style was relaxed and cute, and it was full of healing. In the book, the male protagonist doted on the female protagonist, showing a strong and sweet love complex. I hope you like this fairy's recommendation. Muah ~😗