Shu's route in Dairoku. He's basically a child. He looks and acts like a child. He's technically thousands of years old, but I think we all know that's just a "clever" way to skirt laws. This trope appears all the time in harem anime and I was disappointed to see it in reverse in Dairoku. His appearance is around 12-15 and the MC is in her mid-20's. Even if he was drawn to look like an adult, it's super uncomfortable to date someone who's mentally a child.
Additionally, there's a whole mystery surrounding Shu. He appears in other routes as an aloof figure with unknown motives. When you finally play his route and uncover the mystery, it's lame. It's a lame mystery with a lame conclusion imo.