Artefacts were on display at the University Educational and Cultural Centre . researchers began a search for the wooden plaque and wooden textbook . They were loaned to the museum by Okinawa 's Peace Memorial Museum . Tourist examined the artefacts and offered an apology to researchers .
Artefacts were on display at the Kaetsu Educational and Cultural Centre . Staff launched a search for the wooden plaque and replica textbook . They were loaned to the university by Okinawa's Peace Memorial Museum . Tourist returned the artefacts and offered an apology to staff .