S01E17 — Kyoya's Reluctant Day Out!

Kyoya, half-asleep, is dragged into a commoner's department store by Tamaki and the rest of the boys, who aim to study the life of ordinary people, and therefore understand more about Haruhi - or play. Kyoya ends up meeting Haruhi there, alone, and they find it interesting how each other views their lives. Towards the end, Tamaki makes a call for a "lost child", who turns out to be Kyoya, which makes Kyoya even angrier at Tamaki than he already is.