This game is titled Time Hollow in North America and Europe, and Time Hollow: Uwareta Kako o Motome in Japan.
Alternate ending sequence
Do not open the final hole in your bedroom. Walk back outside and encounter Sox. He will then appear at almost every location. Visit the vacant place, your house, Vin's house, park, Chronos, library and talk to Sara. Ethan will realize that there might be more than one Sox. Open the final hole to see bonus dialogue. Sox will say "Thanks for everything, Ethan." Ethan will think "(Good luck).", and Sox will think "(Same to you, Ethan)."
Strategy guides from GameFAQs