3-tsu no Kagi no Heya Kara no Dasshutsu (3つの鍵の部屋からの脱出, Escape From the Room With the Three Keys) is an escape room Flash game developed by Yomino Kagura and one of many escape room games made by them. This iteration puts emphasis on having to find three special keys. Keys are often used to unlock things in these kinds of games. Or maybe they aren't sometimes. Maybe the keys unlock things another way. You're gonna have to search for clues and use some more unconventional thinking if you're gonna get out of the room.
Rxser here thankfully already knows how to use the keys and escapes the room in record time.