Responses
When he read his diary and found Hakyung's ring that's when all his memories returned. As for more specific, when they go all the way for the first time and it keeps shifting to the diary and ring on the office tableヾ(❀╹◡╹)ﾉ~
BEST MANHWA OF ALL TIME IDEC WHEN DID YOONSUNG REGAIN HIS MEMORIES EXACTLY DID THEY MENTION IT ? idk if i missed it