The sound of quiet, peaceful breathing during deep sleep.
At its core, is a Japanese-developed puzzle and adventure game that focuses on a "stealth" and interaction mechanic. The title itself is an onomatopoeia: Utouto (うとうと): To doze off or be half-asleep. utouto suyasuya
電車の中でうとうとしてしまった。 Densha no naka de utouto shite shimatta. "I dozed off on the train." The sound of quiet, peaceful breathing during deep sleep