It's hard to say for sure. Manhwa often have twist and turns. The boy next door could be a vampire if the story takes a supernatural turn and reveals it later on.
Overall, 'Do It Next Door' manhwa could be about various themes like love, friendship, or mystery within a neighborhood setting. Maybe there are secrets being uncovered or heartwarming moments shared among the characters.
There were a few novels that were somewhat similar to " The Prince Charming Proposes Again Today ", which told the story of the female lead and the cold Prince Charming living next door. I recommend the following two novels to you: " Mr. Huo, Let's Fall in Love " and " The Adonis Who Arrives Next Door ". The former told the story of the female protagonist living in the house of the male god next door to avoid the jerk's reconciliation. She found that the male god was actually the heir of a wealthy family. He was cold and heartless, but he often asked about her well-being. The latter was about the female lead being pestered by CEO Lu's dog next door, which attracted the attention of the national goddess. There were many interesting lines and interactions in the story. I hope you like my recommendation.
"Dear and Loved" was a short romance novel written by Mo Bao Fei Bao. Its original name was "Stewed Squid with Honey Sauce." The story was about Tong Nian being coerced by his friend to watch the video for an hour in an internet cafe. The novel was later adapted into a TV series,"Dear Loved," with Yang Zi and Li Xian as the main actors. There were other related novels about "Dear", such as "Dear (Ghost Ugly)". However, the search results did not provide any detailed information about the content and plot of the novel.
"Dear and Loved" was a short romance novel written by Mo Bao Fei Bao. Its original name was "Stewed Squid with Honey Sauce." The story was about Tong Nian being coerced by his friend to watch the video for an hour in an internet cafe. The novel was later adapted into a TV series,"Dear Loved," with Yang Zi and Li Xian as the main actors. There were other related novels about "Dear", such as "Dear (Ghost Ugly)".
Dear, the cast list that I love includes Yang Zi, Li Xian, and Hu Yitian. Yang Zi played Tong Nian, a lively and cute loli singer who was also a computer "genius" who skipped a grade to study for a master's degree. Li Xian played Han Shangyan, a hot-blooded young man who was determined to fight for his country and lead a group of young players to fight for the world championship. Hu Yitian played Wu Bai, the captain of Team K&K, who was also an outstanding computer genius. These are my dear, beloved main actors.