Let me recommend you a few 2D system novels, including Harem! The first was the "Quick Wear: Battle for Favor System". In order to return to the modern world, the female protagonist had to complete the battle for favor through the system. The unique setting was very attractive! There's also "My System Is A Lawful Loli", the male lead transmigrated to another world and discovered that the system was actually a Loli, starting the story of interacting with a 2D beautiful girl, super cute ~ Finally, I recommend a harem series,"Douluo's 2D Summoning", the male lead not only can summon 2D characters, but also can meet Tang San! Haha, more than addictive. I hope you will like these novels.💕