The female protagonist was a tennis fan before she transmigrated. Her favorite person was a ninja. However, she was later sent to Lihai University because of her sister's framing. She was protected by the people of Lihai University. If you like novels with time-travel and tennis elements, you can read them. I hope you like this fairy's recommendation. Muah ~π
πI recommend "The King of the Net: Early Summer" to you. The female protagonist, Mi Yue Xue Xi, traveled to the world of the tennis prince and became the sister of the ace player of Lihai University, Echizen Chuxia. At first, the female protagonist hated the male protagonist, but as the story progressed, the sweet love between the two slowly warmed up. I hope you like this fairy's recommendation. Muah ~π
πI recommend the novel "The Prince of Tennis-Wavering Women's Academy" to you. It tells the story of the female protagonist, Yuri Sugimoto, who had just arrived at Rikai University. She had a very strange personality and was not a social person. She had a conflict with the captain of the Women's Academy, Kazuji Toyama, during the freshman enrollment ceremony. At the same time, her identical brother, Sugimoto Masayoshi, was also studying at Rikai University. He became a member of the tennis club at Rikai University and had outstanding results. Later, Yuri also joined the tennis club and became friends with Kazuki. She began to gradually integrate into the group. I hope you like this fairy's recommendation. Muah ~π
I can't provide any romantic Doujinshi because it's a Japanese anime and the gender characters in the anime are usually not set to have a clear relationship. If you are looking for other types of Doujinshi, I can give you some suggestions. For example, you can try to find a romance novel about the interaction between the male and female protagonists to satisfy your taste. Or you can look for a romance novel with the background of the Internet King, in which the male and female protagonists cross over to the Internet King world and meet. I hope these suggestions can help you!
I recommend the two books,"The Net King: Edogawa Sakurazu-ichi" and "The School Hunk Is A Teacher: A Cold-looking Assistant Teacher, Please Give Me Questions". The female protagonist of "The King of the Net: Edogawa Sakurazu-ichi" was the king of the Qingxue Women's Network. She was a genius and had the plot of being an assistant teacher at Lihai University. The female lead of "School Hunk Is a Teacher: Cold-hearted Teaching Assistant, Please Give Me a Question", Chen Che, was a cute and funny Weibo celebrity and also a teaching assistant. These two books have plots of female geniuses and teaching assistants. They are also light novels and youth campus novels. I believe you will like them. I hope you like this fairy's recommendation. Muah ~π
The novel I recommend to you is "The Net King: Early Summer". The female protagonist is called Mi Yue Xue Xi. She was originally from Lihai University, but later went to the Ice Emperor. The story was about her and Akira Yukimura becoming lovers. I hope you like this fairy's recommendation. Muah ~π
My answer doesn't seem to match the information you provided. The name of the novel you provided is " The King of the Net " and the name of the novel I mentioned before is " The Prince of Tennis'. Although these two novels were both about tennis, their plots and character settings were very different. The Prince of Tennis was a Japanese manga and anime that told the story of a group of young tennis players growing up and fighting in the process of competition and training between high school and university. One of the female leads was a second-year student of Rikai University, Moeon Ueki Shiraishi. She was misunderstood by Yukomura Seiichi and others, but gradually discovered her love and sense of mission for tennis through her interactions with these people. As for protecting the heirs of the Eight Corporations, it might be a plot in the novel, but I didn't mention the specific details. If you have any other questions about the novel, I will be more than happy to help you.
It was often mentioned in online novels that the Prince of Lihai University was an anime based on the secondary school affiliated to Lihai University. In this work, Lihai University, as the protagonist's school, showed many plots about tennis and school life.
I recommend "The Flower of Rebirth Blossoms on a Stranger Road" to you. The female protagonist of this book also transmigrated to ancient times and became a silly concubine's daughter. However, she learned medicine and made drugs and turned into a powerful woman. I hope you like this fairy's recommendation. Muah ~π
πThe book I recommend to you is "Quick Wear: The King of the Net's Male God Guide". The female protagonist was reborn into the world of tennis princes and became a coach at Lihai University. When she was young, she was neighbors with Igo Shinji and primary school classmates with Ganzhenzhi and Liu Lianer. In addition, she also fell in love with Ryuuma Echizen and captured Saeki Torujiro and other boys. I hope you like this fairy's recommendation. Muah ~π
According to the information you gave me, I recommend the "Scar in the Sky of the Prince of Tennis" to you. This was a Doujinshi novel about the tennis prince, with Yukimura Seiichi as the male lead. The female lead was called Asuka Amagi, the older sister of Ryuuma Echizen, and the twin sister who was born at the same time as Yukimura Seiichi. Asuka had left Tachikai University due to a misunderstanding. The Jing City had been searching for her ever since. The plot of the novel was compact and interesting. It was very suitable for fans of the Prince of tennis. I hope you like this fairy's recommendation. Muah ~π