Traumatised by One-Way Ticket

The Tokyo office manager explained me that the travel agent refused to issue me an one-way ticket from Tokyo to Kuala Lumpur because

1. I might be blocked in Narita airport by Japanese immigration officer - It is definitely ridiculous. Japanese immigration officer only wants to make sure that you have the ticket leaving Japan, not the ticket coming back to Japan.

2. The Malaysia immigration might refuse my entry because I can show no proof of leaving the country. - What? You can easily go to Singapore by train, by bus within 3 hours. Says who you need to fly out of Kuala Lumpur to another country? In addition, I have never been questioned how I am going to leave Kuala Lumpur in my half dozen times of visiting. I am granded the 90-day visitor's VISA on landing.

3. The airline might refused me boarding the air plane because there is a chance Malaysia goverment could refuse my entry - It is highly impossible however, I have explained them that I will purchase a ticket to leave the country if that's the case, they still refuse to issue me the ticket.

I spent half an hour explaining to the brain-damaged travel agent with the best of my patience. She could only reply me "this is written in the hand book, I cannot sell you the one-way ticket but you can buy a round trip ticket".