Chiyou's the game's main shopkeep, trading with YI with the goal of repairing his brother. He is a poet and scholar who has an extreme love for the arts, especially taking interest in Shuanshuan's works. Chiyou often speaks very formally, sounding partially robotic due to his half-mechanical nature as well as being a scholar, however he is more emotional than other robotic characters throughout the game.

https://drive.google.com/drive/folders/1pOTzLkLPQbYKjFWih7E8UPhe2i3Fcw8h

Line Context and Tone: 

Line 1: This conversation is where Yi first meets Chiyou and learns of his unique nature as a weapon-turned scholar. This conversation can happen in a variety of places depending on when you first decide to talk to Chiyou. This is before we learn of Chiyou's motivations to save his brother, where he's first introducing himself as a scholar and trying to make a deal with Yi to repair himself. 

Line 2: This conversation happens upon running into Chiyou within the factory, though not necessarily, the player has most likely both already met two sols and Chiyou previously. This is where we learn of Chiyou's wish to save his brother, showing the first bit of his more emotional side with his request to Yi.

Line 3: After Chiyou saves Yi when he passes out after prison, Chiyou moves into the four seasons pavillion, where we get to learn more about him as well as continue to barter. Also, throughout the story, as Yi finds Solarian artifacts he can give them to Shuanshuan, who will use them to learn different skills, including painting. Eventually when Chiyou moves into the four seasons and after Shuanshuan paints a portait of Yi, Yi comes across Chiyou marvelling at Shuanshuan's work. This is where we see Chiyou's scholarly nature, getting excited about these unique paintings.