Store manager Katsuyuki Aono said worried staff called security after Collins went behind a service counter in the food department in the basement of the store.
''When the security guard from our store arrived, Mr Collins pulled out a knife and placed it on the counter,'' Mr Aono told the Herald.
It was not known why he went behind the counter.
''The security guard then took the knife and called the police.''
Officers arrived and arrested Collins.
''He was perspiring heavily and appeared very anxious and unstable. He was acting very strange and was looking around in different places behind the counter.
''He was speaking in English, but the staff couldn't understand what he was saying.''
Mr Aono said Collins did not threaten staff, was not violent, and did not try to take money.
''We really couldn't understand what he was doing - he was just behaving in a strange and abnormal way.
Saturday early evening is a busy time for our store and there were a lot of customers.''
Staff did not recognise Collins and were surprised to hear he was an All Black.
''We hope he is able to recover soon and return to playing rugby.''
Japanese police have permission to keep Collins in custody for another 10 days.
|May 21||Pyongyang fires sixth 'missile' in three days|
|North Korea fired two more "projectiles" into the Sea of Japan on Monday, the latest in a series of drills condemned by South Korea and U.N. Secretary General Ban Ki Moon. (Japan Times )|
|May 20||Sub lurking near Okinawa identified, but Onodera mum|
|Defense Minister Itsunori Onodera said Monday the government has identified the country whose submarine was detected while submerged the previous day near Okinawa and will call for such encroachments to cease. (Japan Times )|
|May 20||634-meter high Tokyo Skytree attracts 6.34 mil. visitors|
|The number of visitors to the observation deck of Tokyo Skytree, the world's tallest broadcasting tower at 634 meters, reached 6.34 million on Monday, matching the numerals of its height two days before the first anniversary of its opening, according to the operator. (Kyodo )|
|May 20||Hashimoto says not to withdraw comfort women remarks|
|Toru Hashimoto, co-head of Nippon Ishin No Kai (Japan Restoration Party), told Shintaro Ishihara, the other co-leader of the Japanese opposition party, on Sunday that he has no intention to withdraw his recent remarks that have triggered outrage both at home and abroad. (Jiji Press )|
|May 20||Abe to focus on advanced medical technology|
|Japanese Prime Minister Shinzo Abe on Sunday underscored his government's intention to help promote the state-of-the-art medical technologies. (Jiji Press )|
|May 21||Claim filed against Yamaguchi-gumi top bosses for arson death in Nagoya|
|The parents of a nightclub worker killed in an arson fire three years ago filed a suit in the Nagoya District Court on Monday seeking damages against top members of the Yamaguchi-gumi organized crime group. (Tokyo Reporter)|
|May 21||Senior Kyodo News official dismissed over improper act|
|Senior Kyodo News Official Dismissed over Improper Act (Jiji Press )|
|May 20||Saitama cops bust massive child porn DVD operation|
|Saitama and Okayama prefectural police last week arrested the manager of an online porn DVD operation that specialized in films featuring children. (Tokyo Reporter)|
|May 19||Japan's child kidnapping problem|
|Dozens of American children are abducted to Japan every year-not by strangers, but by parents after messy divorces. (thedailybeast.com )|
|May 18||5-year-old boy's hand gets caught in shopping mall escalator|
|A 5-year-old boy sustained an injury at a shopping mall in Nagoya on Friday after his hand became trapped in an escalator. (Japan Today )|
|May 18||Woman stabbed by stalker despite asking police for help|
|A 24-year-old woman was in a serious condition Friday after being stabbed by a man whom she reported to police for stalking her in Kurashiki, Okayama Prefecture. (Japan Today )|
|May 18||70-year-old woman rescued from toilet after 3-day ordeal|
|A 70-year-old woman has been rescued from a toilet in which she had been waiting for help for three days, Hiroshima police said Friday. (Japan Today )|
|May 18||Traditional dance performed at Nikko temple|
|A traditional dance was performed on Friday at an ancient temple in Nikko City, northeast of Tokyo. (NHK )|
|May 18||China cracks down on over-the-top anti-Japan dramas|
|China's television regulator has ordered a crackdown on dramas about the country's battles with Japan during and before World War Two and demanded they be more serious, state media said on Friday, following viewer complaints about ludicrous storylines. (Reuters )|
|May 17||Bear shot dead after entering school in Ishikawa|
|A bear was shot dead after it wandered into a school in Kanazawa, Ishikawa Prefecture, on Thursday. (Japan Today )|