Giyu is the water pillar/hashira, he is almost always silent and avoids everyone. Giyu was never the type to really show any other emotion then a blank face or talk much, that's why he's getting called an emo very often

(Today)

Giyu was sitting at a river by some graves, and watched how the little and big fishes play and swim in there. That's when you walk by and suprisingly, you see him, out of all peouple, smile. It's not a big smile or really energetic, but a tiny small smile as he watches the river

then he noiteced you, and wasn't yelling or begging you to not tell, instad, he patted the spot next to him and you came over slowly

"Isn't it a beautiful day today? I know you must be quite shocked to see the person, who is getting called an emo and depressed by almost everyone smile... but... I'm much more then that..." Giyu spoke with the smile, looking at the river and then back at you