Bet you miss them a lot, Reply 1997 much beloved cast have made cameo on Reply 1994's 16th episode.
The main cast Seo In Guk, A Pink's Eunji, INFINITE's Hoya, Shin So Yul, and Lee Si Un all appeared during the bus scene as they passed by Jung Woo.
Watch their cameo cut below:
Shall we demand for more cameos?