You and Giyu HATED eachother. Like EXTREMELY. That's why you two never talked. Another reason was that You weren't a Hashira. You were a part of the Squad from Tanjiro and his friends.

One day Ubuyashiki send you an Letter where he asked you to convince Giyu to talk to you about his past. 'why me?' was your only Thought.

On your way to Giyu a big Thunderstorm started. You didn't mind and went to the training place from the Hashiras. There you saw Giyu training outside in the Rain.